- Hinge Binder Scaffold Hopping Identifies Potent Calcium/Calmodulin-Dependent Protein Kinase Kinase 2 (CAMKK2) Inhibitor Chemotypes
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CAMKK2 is a serine/threonine kinase and an activator of AMPK whose dysregulation is linked with multiple diseases. Unfortunately, STO-609, the tool inhibitor commonly used to probe CAMKK2 signaling, has limitations. To identify promising scaffolds as starting points for the development of high-quality CAMKK2 chemical probes, we utilized a hinge-binding scaffold hopping strategy to design new CAMKK2 inhibitors. Starting from the potent but promiscuous disubstituted 7-azaindole GSK650934, a total of 32 compounds, composed of single-ring, 5,6-, and 6,6-fused heteroaromatic cores, were synthesized. The compound set was specifically designed to probe interactions with the kinase hinge-binding residues. Compared to GSK650394 and STO-609, 13 compounds displayed similar or better CAMKK2 inhibitory potency in vitro, while compounds 13g and 45 had improved selectivity for CAMKK2 across the kinome. Our systematic survey of hinge-binding chemotypes identified several potent and selective inhibitors of CAMKK2 to serve as starting points for medicinal chemistry programs.
- Asquith, Christopher R. M.,Awad, Dominik,Catta-Preta, Carolina M. C.,Cou?ago, Rafael M.,Drewry, David H.,Eduful, Benjamin J.,Frigo, Daniel E.,Hossain, Mohammad Anwar,Langendorf, Christopher G.,Liang, Yi,Lin, Chenchu,Nay, Kévin,O'Byrne, Sean N.,Oakhill, Jonathan S.,Picado, Alfredo,Pilotte, Joseph R.,Pulliam, Thomas L.,Santiago, André De S.,Scott, John W.,Temme, Louisa,Wells, Carrow I.,Willson, Timothy M.,Zonzini Ramos, Priscila,Zuercher, William J.
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- Esterification with aromatic acyl-1,2,4-triazole Catalyzed by weak base at the rate comparable to acyl chloride
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Benzoyl-1,2,4-triazole underwent esterification with a primary alcohol in the presence of 4-(N,N-dimethylamino)pyridine (DMAP) catalyst at the rate comparable to benzoyl chloride. The kinetic study concluded that the reaction proceeds in a similar mechanism to carboxylic acid anhydride and is thus sensitive to the steric hindrance of alcohol. As the esterification of benzoyl-1,2,4-triazole did not afford acidic by-product and require an equimolar or more amount of base, it is effective for the protection of acid-sensitive alcohol and polyester synthesis.
- Kohsaka, Yasuhiro,Homma, Kazumasa,Sugiyama, Susumu,Kimura, Yoshikazu
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- Chiral sulfur-reagents for the preparation of optically active epoxides
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Acyclic chiral sulfides which could be easily synthesized in both enantiomeric forms leading to poor yields and/or to racemic epoxides, Eliel's oxathiane reagent was used and proved to provide chiral trans diarylepoxides in high yield (70-80%) and enantiomeric purities up to 70-100%, with no rearrangement problems. It was also found that phase-transfer conditions were the easiest and the most efficient for these reactions.
- Solladie-Cavallo,Adib
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- Synthesis of N-(protected)aminophthalimides: Application to the synthesis of singly labelled isoniazid
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The synthesis of a series of N-(protected)aminophthalimides and the removal of their phthaloyl group leading to N-(protected) or N,N-bis(protected)hydrazines is described. As illustrated by the synthesis of monolabelled isoniazid 3b*, this strategy can be utilized for the preparation of monolabelled substituted hydrazines.
- Brosse, Nicolas,Pinto, Maria-Fatima,Jamart-Gregoire, Brigitte
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- Synthesis of water soluble hyperbranched polyurethanes using selective activation of AB2 monomers
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The synthesis of a novel water-soluble hyperbranched polyurethane is described. The synthetic strategy involves a new approach to hyperbranched polymerization through the selective activation of the A functionality of the unprotected of AB2 monomer. 1,1′-Carbonyl diimidazole is added at room temperature to an amino-diol monomer with the corresponding selective formation of an active carboxamide and no detectable reaction at the hydroxyl B functional groups. The active monomer self-condenses to form hyperbranched polyurethanes with measured degrees of branching equaling 0.6 and Ma up to 11 000 Da. A series of model reactions has been conducted to confirm the polymerization mechanism, and ideally branched model molecules have been used to assign the 15N NMR spectra of the hyperbranched polymers. Reaction conditions have been varied, and the factors affecting the polymerization are discussed.
- Rannard, Steve P.,Davis, Nicola J.,Herbert, Ian
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- Microwave-promoted conversion of heterocyclic amines to corresponding amides under solvent-free conditions
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An array of heterocyclic amides was synthesized efficiently by combining corresponding amines and benzoyl chloride in one-pot under microwave irradiation. The reaction times were shorter, yields were higher. What is more, the regioselectivity was excellent, which made the protocol support us an entry to selective protection of diverse amino groups.
- Li, Yanqiu,Wang, Yulu,Wang, Jinye
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- Amidations Using N,N′-Carbonyldiimidazole: Remarkable Rate Enhancement by Carbon Dioxide
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Carbon dioxide catalyzes the reaction of imidazolides with amines to form amides. A substantial rate enhancement is observed in the presence of CO 2 compared to the CO2-free case. The scope and limitations of this reaction are discussed.
- Vaidyanathan, Rajappa,Kalthod, Vikram G.,Ngo, Duc P.,Manley, Jerad M.,Lapekas, Sean P.
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- Mild and useful method for n-acylation of amines
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Iodine is found to promote quantitative N-acylation of primary and secondary amines (aliphatic and aromatic) in a very short time with an equimolar amount of acetyl chloride and benzoyl chloride under solvent-free conditions at room temperature. This catalytic acylation of amines offers an additional useful method for the acetylation using acetyl chloride instead of acetic anhydride and other acetylating agents. This method is also useful in the N-acylation of heterocycles. Mild reaction condition, high selectivity, efficiency, and good yields are some of the major advantages of the procedure.
- Phukan, Kandarpa,Ganguly, Mausumi,Devi, Nirada
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- New bioactive triaryl triglyceride esters: Synthesis, characterization and biological activities
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Four new bioactive aryl triester derivatives of glycerol and benzoic acids were synthesized. The synthetic compounds were studied for their antimicrobial and urease inhibition activities. Esterification was carried out by using carbonyldiimidazole to enhance the acyl elimination addition reaction with benzoic acid derivatives. The structure of triglycerides were studied by EI-MS,1H,13C-NMR, FT-IR and elemental analysis. All synthetic compounds showed urease inhibition activity with highest value of IC50 value 22.4 ± 0.45 μM which is nearest to standard thiourea IC50 value (21.6 ± 0.12 μM). Except compound (3d), all other compounds exhibited antimicrobial activity against Streptococcus pneumoniae, Staphylococcus epidermidis, Bacillus pumilus, Escherichia coli, Pseudomonas aeruginosa and Candida albican.
- Arshad, Tanzila,Sheikh, Hamdullah Khadim,Kazmi, Mehdi Hassan,Farheen, Sadia,Sohail, Tehmina,Lateef, Mehreen
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- Synthesis, characterization, and in vitro evaluation of novel ruthenium(II) η6-arene imidazole complexes
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Ten complexes of general formula [Ru(η6-arene)Cl 2(L)], [Ru(η6-arene)Cl(L)2][X], and [Ru(η6-arene)(L)3][X]2 (η6- arene = benzene, p-cymene; L = imidazole, benzimidazole, N-methylimidazole, N-butylimidazole, N-vinylimidazole, N-benzoylimidazole; X = Cl, BF4, BPh4) have been prepared and characterized by spectroscopy. The structures of five representative compounds have been established in the solid state by single-crystal X-ray diffraction. All the new compounds were assessed by the same in vitro screening assays applied to [imidazole-H][trans-RuCl 4(DMSO)(imidazole)] (NAMI-A) and [Ru(η6-arene)Cl 2(1,3,5-triaza-7-phosphaadamantane)] (RAPTA) compounds. It was found that the new compounds show essentially the same order of cytotoxicity as the RAPTA compounds toward cancer cells. Several of the compounds were selective toward cancer cells in that they were less (or not) cytotoxic toward nontumorigenic cells that are used to model healthy human cells. Thus, two of the compounds, [Ru(η6-p-cymene)Cl(vinylimid)2][Cl] (vinylimid = N-vinylimidazole) and [Ru(η6-benzene)(mimid) 3][BF4]2 (mimid = N-methylimidazole), have been selected for a more detailed in vivo evaluation.
- Vock, Carsten A.,Scolaro, Claudine,Phillips, Andrew D.,Scopelliti, Rosario,Sava, Gianni,Dyson, Paul J.
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- Silver-Catalyzed Acyl Nitrene Transfer Reactions Involving Dioxazolones: Direct Assembly of N-Acylureas
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Dioxazolones and isocyanides are useful synthetic building blocks, and have attracted significant attention from researchers. However, the silver-catalyzed nitrene transfer reaction of dioxazolones has not been investigated to date. Herein, a silver-catalyzed acyl nitrene transfer reaction involving dioxazolones, isocyanides, and water was realized in the presence of Ag2O to afford a series of N-acylureas in moderate to good yields.
- Yang, Zheng-Lin,Xu, Xin-Liang,Chen, Xue-Rong,Mao, Zhi-Feng,Zhou, Yi-Feng
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supporting information
p. 648 - 652
(2020/12/21)
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- Combined Photoredox and Carbene Catalysis for the Synthesis of γ-Aryloxy Ketones
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N-heterocyclic carbenes (NHCs) have emerged as catalysts for the construction of C?C bonds in the synthesis of substituted ketones under single-electron processes. Despite these recent reports, there still remains a need to increase the utility and practicality of these reactions by exploring new radical coupling partners. Herein, we report the synthesis of γ-aryloxyketones via combined NHC/photoredox catalysis. In this reaction, an α-aryloxymethyl radical is generated via oxidation of an aryloxymethyl potassium trifluoroborate salt, which is then added into styrene derivatives to provide a stabilized benzylic radical. Subsequent radical-radical coupling reaction with an azolium radical affords the γ-aryloxy ketone products. (Figure presented.).
- Fitzpatrick, Keegan P.,Scheidt, Karl A.,Wang, Pengzhi
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supporting information
(2021/12/16)
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- Combined Photoredox and Carbene Catalysis for the Synthesis of Ketones from Carboxylic Acids
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As a key element in the construction of complex organic scaffolds, the formation of C?C bonds remains a challenge in the field of synthetic organic chemistry. Recent advancements in single-electron chemistry have enabled new methods for the formation of various C?C bonds. Disclosed herein is the development of a novel single-electron reduction of acyl azoliums for the formation of ketones from carboxylic acids. Facile construction of the acyl azolium in situ followed by a radical–radical coupling was made possible merging N-heterocyclic carbene (NHC) and photoredox catalysis. The utility of this protocol in synthesis was showcased in the late-stage functionalization of a variety of pharmaceutical compounds. Preliminary investigations using chiral NHCs demonstrate that enantioselectivity can be achieved, showcasing the advantages of this protocol over alternative methodologies.
- Betori, Rick C.,Davies, Anna V.,Fitzpatrick, Keegan P.,Scheidt, Karl A.
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supporting information
p. 9143 - 9148
(2020/03/30)
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- Sustainable Palladium-Catalyzed Tsuji-Trost Reactions Enabled by Aqueous Micellar Catalysis
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Palladium-catalyzed allylic substitution, or "Tsuji-Trost"reactions, can be run under micellar catalysis conditions featuring not only chemistry in water but also numerous combinations of reaction partners that require low levels of palladium, typically on the order of 1000 ppm (0.1 mol %). These couplings are further characterized by especially mild conditions, leading to a number of cases not previously reported in an aqueous micellar medium. Inclusion of diverse nucleophiles, such as N-H heterocycles, alcohols, dicarbonyl compounds, and sulfonamides is described. Intramolecular cyclizations further illustrate the broad utility of this process. In addition to recycling studies, a multigram scale example is reported, indicative of the prospects for scale up.
- Braga, Felipe C.,Gallou, Fabrice,Lee, Nicholas R.,Lippincott, Daniel J.,Lipshutz, Bruce H.,Moghadam, Farbod A.,Zhu, Bingchun
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supporting information
(2020/07/15)
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- Ketoreductase catalyzed stereoselective bioreduction of α-nitro ketones
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We report here the stereoselective bioreduction of α-nitro ketones catalyzed by ketoreductases (KREDs) with publicly known sequences. YGL039w and RasADH/SyADH were able to reduce 23 class I substrates (1-aryl-2-nitro-1-ethanone (1)) and ten class II substrates (1-aryloxy-3-nitro-2-propanone (4)) to furnish both enantiomers of the corresponding β-nitro alcohols, with good-to-excellent conversions (up to >99%) and enantioselectivities (up to >99% ee) being achieved in most cases. To the best of our knowledge, KRED-mediated reduction of class II α-nitro ketones (1-aryloxy-3-nitro-2-propanone (4)) is unprecedented. Select β-nitro alcohols, including the synthetic intermediates of bioactive molecules (R)-tembamide, (S)-tembamide, (S)-moprolol, (S)-toliprolol and (S)-propanolol, were stereoselectively synthesized in preparative scale with 42% to 90% isolated yields, showcasing the practical potential of our developed system in organic synthesis. Finally, the advantage of using KREDs with known sequence was demonstrated by whole-cell catalysis, in which β-nitro alcohol (R)-2k, the key synthetic intermediate of hypoglycemic natural product (R)-tembamide, was produced in a space-time yield of 178 g L?1 d?1 as well as 95% ee by employing the whole cells of a recombinant E. coli strain coexpressing RasADH and glucose dehydrogenase as the biocatalyst.
- Wang, Zexu,Wu, Xiaofan,Li, Zhining,Huang, Zedu,Chen, Fener
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supporting information
p. 3575 - 3580
(2019/04/14)
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- A convenient synthesis of 2-acyl benzothiazoles/thiazoles from benzothiazole/thiazole and N,N'-carbonyldiimidazole activated carboxylic acids
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A convenient and efficient strategy for the synthesis of 2-acyl benzothiazoles/thiazoles has been developed. The treatment of benzothiazole/thiazole with allylic Grignard reagents readily generates the corresponding 2-Grignard reagents, which is followed by a reaction with N,N'-carbonyldiimidazole activated carboxylic acids to afford various 2-acyl benzothiazoles/thiazoles products. The synthetic method is applicable to a wide array of carboxylic acids and allows easy access to 2-acyl benzothiazoles/thiazoles with considerable yields under mild reaction conditions.
- Huang, Tonghui,Wu, Xin,Yu, Yongbo,An, Lin,Yin, Xiaoxing
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supporting information
p. 1667 - 1670
(2019/06/04)
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- Efficient CDI/CH3SO3H-catalyzed, microwave-assisted synthesis of 2-substituted benzothiazoles
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CDI combined with CH3SO3H was found to be highly effective for the cyclization of 2-aminothiophenol derivatives with carboxylic acids under MW condition. Fourteen benzothiazole derivatives were synthesized in good yield and their structures were characterized by1H-NMR,13C-NMR, IR and mass spectrometry. This simple, rapid synthetic method is believed to provide a useful process for the synthesis of 2-substituted benzothiazole compounds.
- Li, Yao-Wei,Zhang, Pei-Ming,Li, Rui,Bai, Yan,Yu, Yu,Gan, Zong-Jie
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supporting information
p. 34 - 39
(2019/05/04)
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- Synthesis of Amides from Alcohols and Amines Through a Domino Oxidative Amidation and Telescoped Transamidation Process
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The amide bond formation is of paramount importance in organic synthesis, both within academic research and industrial development and manufacturing of pharmaceutical chemicals and other biologically active compounds. Despite this fact, as well as the ever-increasing treatment costs of side streams and other environmental concerns regarding handling and transportation of hazardous reagents, contemporary synthesis has elicited few new reactions and methods for the preparation of amides. Herein, we reveal a high yielding and expedite two-step telescoped synthetic process that comprises a domino oxidative amidation and transamidation for the creation of amides. The process utilizes alcohols and amines as reaction pairs with TEMPO and Fe ions as catalytic system and 1,3-dichloro-5,5-dimethyl hydantoin as a terminal oxidant. The oxidative amidation and transamidation process is conducted under benign reaction conditions and short reaction time (≈ 30 min.) in a two-step telescoped fashion by means of a multi-jet oscillating disk (MJOD) continuous-flow reactor platform. The disclosed process integrates alcohol oxidation and amide formation to afford target amide in yields up to 90 %. The method operates with both primary and secondary amines together, but was hampered when bulky amines and/or alcohols were used as reagent/substrate.
- Drageset, Audun,Bj?rsvik, Hans-René
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p. 4436 - 4445
(2018/09/11)
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- Preliminary SAR and biological evaluation of antitubercular triazolothiadiazine derivatives against drug-susceptible and drug-resistant Mtb strains
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Following up the SAR study of triazolothiadiazoles for their antitubercular activities targeting Mt SD in our previous study, on the principle of scaffold hopping, the C3 and C6 positions of triazolothiadiazine were examined systematically to define a preliminary structure–activity relationship (SAR) with respect to biological activity. This study herein highlights the potential of two highly potent advanced leads 6c-3, 6g-3 and several other compounds with comparable potencies as promising new candidates for the treatment of TB (6c-3, MIC-H37Rv?=?0.25?μg/mL; MIC-MDRTB?=?2.0?μg/mL; MIC-RDRTB?=?0.25?μg/mL; Mt SD-IC50?=?86.39?μg/mL; and 6g-3, MIC-H37Rv?=?1.0?μg/mL; MIC-MDRTB?=?4.0?μg/mL; MIC-RDRTB?=?2.0?μg/mL; Mt SD-IC50?=?73.57?μg/mL). Compounds 6c-3 and 6g-3 possessed a para-nitro phenyl at the 6 position showed low Vero and HepG2 cells toxicity, turning out to be two excellent lead candidates for preclinical trials. In addition, in vitro Mt SD inhibitory assay indicates that Mt SD is at least one of the targets for their antitubercular activity. Thus, they may turn out to be promising multidrug-resistance-reversing agents.
- Li, Ziqiang,Bai, Xiaoguang,Deng, Qi,Zhang, Guoning,Zhou, Lei,Liu, Yishuang,Wang, Juxian,Wang, Yucheng
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p. 213 - 220
(2016/12/18)
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- Chemoselective acylation of 2-amino-8-quinolinol in the generation of C2-amides or C8-esters
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Two different ways to carry out the chemoselective acylation of 2-amino-8-quinolinol with unique features to generate C2-amides or C8-esters were developed. The coupling reaction with a variety of carboxylic acids using EDCI and DMAP provided C8-ester derivatives, whereas N-heteroaromatic acids were not introduced on the C8-hydroxy group, but rather on the C2-amino group under the same conditions. To obtain C2-amides selectively, the anionic nucleophile from 2-amino-8-quinolinol was treated with less reactive acyl imidazolides or esters.
- Park, Yongseok,Fei, Xiang,Yuan, Yue,Lee, Sanha,Hur, Joonseong,Park, Sung Jean,Jung, Jae-Kyung,Seo, Seung-Yong
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p. 41955 - 41961
(2017/09/12)
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- Elucidation of the E-Amide Preference of N-Acyl Azoles
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The conformational properties of N-acyl azoles (imidazole, pyrazole, and triazole) were examined. The N-2′,4′,6′-trichlorobenzoyl azoles were stable in methanol at room temperature, and no hydrolyzed products were observed over 7 days in the presence of 5% trifluoroacetic acid or 5% triethylamine in CDCl3. The high stability may be explained by the double-bond amide character caused by the steric hindrance due to the ortho-substituents in the benzoyl group. While specific E-amide preferences were observed in N-acyl pyrazoles/triazoles, the amides of the imidazoles gave a mixture of E and Z. One of the conceivable ideas to rationalize this conformational preference may be repulsive interaction between two sets of lone-pair electrons on the pyrazole 2-nitrogen (nN) and the carbonyl oxygen atoms (nO) in the Z-conformation of N-acyl pyrazoles/triazoles. However, analysis of orbital interactions suggested that in the case of the E-conformation of N-acyl pyrazoles, such electron repulsion is small because of distance. The interbond energy calculations suggested that the Z-conformer is involved in strong vicinal σ-σ repulsion along the amide linkage between the σN1N2 and σC1C2 orbitals in the anti-periplanar arrangement and between the σN1C5 and σC1C2 orbitals in the syn-periplanar arrangement, which lead to the overwhelming E-preference in N-acyl pyrazoles/triazoles. In the case of N-acyl imidazoles, similar vicinal σ-σ repulsions were counterbalanced, leading to a weak preference for the E-conformer over the Z-conformer. The chemically stable and E-preferring N-acyl azoles may be utilized as scaffolds in future drug design.
- Takahashi, Yuka,Ikeda, Hirotaka,Kanase, Yuki,Makino, Kosho,Tabata, Hidetsugu,Oshitari, Tetsuta,Inagaki, Satoshi,Otani, Yuko,Natsugari, Hideaki,Takahashi, Hideyo,Ohwada, Tomohiko
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p. 11370 - 11382
(2017/11/10)
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- Liposomal circular dichroism (L-Cd) of arenoyl derivatives of sphingolipids. Amplification of cotton effects in ordered lipid bilayers
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Liposomal circular dichroism (L-CD) of acyclic amino alcohols exhibit amplification of Cotton effects when measured in highly uniform, unilamellar liposomes. The effect is likely due to intermolecular associations—H-aggregates—that self-assemble spontaneously within the lipid bilayer, and persists over long time scales. L-CD spectra of N,O,O-tri-(6′methoxy-2′naphthoyl)-D-erythro-sphingosine, or the corresponding dihydro-derivative (sphinganine), shows ~10-fold amplification of magnitudes of Cotton effects over conventional CD spectra recorded in isotropic solution.
- Molinski, Tadeusz F.,Broaddus, Caroline D,Morinaka, Brandon I
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- Ruthenium(II) complexes encompassing 2-oxo-1,2-dihydroquinoline-3-carbaldehyde thiosemicarbazone hybrid ligand: A new versatile potential catalyst for dehydrogenative amide synthesis
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Ruthenium(II) complexes (1–6) supported by a series of 2-oxo-1,2-dihydroquinoline-3-carbaldehyde substituted thiosemicarbazone ligands [2-oxo-1,2-dihydroquinoline-3-carbaldehyde thiosemicarbazone (L1), 2-oxo-1,2-dihydroquinoline-3-carbaldehyde N-methyl thiosemicarbazone (L2), 2-oxo-1,2-dihydroquinoline-3-carbaldehyde N-phenylthiosemicarbazone (L3)] have been synthesized and structurally characterized by analytical, spectroscopic methods and X-ray crystallographic technique. The studies revealed that the ligands act as mononegative tridentate in ruthenium(II) complexes and a distorted octahedral geometry has been proposed for the complexes. In addition, the complexes have been found to catalyze the amidation of alcohols with amines in the presence of KtBuO–toluene system. The catalyst 3 displayed higher activity in substrates, including phenyl-, pyridine-, furan-, and thiophene-substituted alcohols with primary and secondary amines. The protocol is highly attractive because of easily available starting materials, high atom efficiency and environmental friendliness.
- Selvamurugan, Sellappan,Ramachandran, Rangasamy,Prakash, Govindan,Nirmala, Muthukumaran,Viswanathamurthi, Periasamy,Fujiwara, Shoji,Endo, Akira
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- An Environmentally Sustainable Mechanochemical Route to Hydroxamic Acid Derivatives
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An operationally simple, and cost efficient conversion of carboxylic acids into hydroxamic acid derivatives via a high-energy mechanochemical activation is presented. This ball milling methodology was applied to a wide variety of carboxylic acids dramatically improving purification issues associated with this class of molecules, which still remain one of the main bottlenecks of classical methodologies. (Figure presented.).
- Mocci, Rita,De Luca, Lidia,Delogu, Francesco,Porcheddu, Andrea
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supporting information
p. 3135 - 3144
(2016/10/09)
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- Organo-functionalized trimethoxysilanes featuring thioester linkage: Synthetic and UV–Vis spectral investigations
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The current work reveals a series of new organo-functionalized trimethoxysilanes (OfTMS) linked via a 3C tether to the thioester group along with the inclusion of versatile aromatic and heteroaromatic sequences. The synthetic procedure implicates the one-pot thioesterification reaction of the precursor carboxylic acids (1a-r) with 3-mercaptopropyltrimethoxysilane (MPTMS), stimulated by 1,1′-carbonyldiimidazole (CDI). The OfTMS have been attentively characterized by elemental analysis, infrared and [1H, 13C] NMR spectroscopic techniques. The UV–Vis absorption behaviour demonstrates that the alkoxysilanes possess high sensitivity to the changes caused in the environment on account of different substitutions. Furthermore, the solvent effect on the absorption spectra has been scrutinized and quantified using the Kamlet-Taft approach. Importantly, the fabricated stable alkoxysilanes can be aspired for advance applications in the field of material science.
- Singh, Gurjaspreet,Rani, Sunita,Saroa, Amandeep,Arora, Aanchal
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- Ruthenium(II) carbonyl complexes containing bidentate 2-oxo-1,2-dihydroquinoline-3-carbaldehyde hydrazone ligands as efficient catalysts for catalytic amidation reaction
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The coordination behavior of 2-oxo-1,2-dihydroquinoline-3-carbaldehyde hydrazone ligands in ruthenium(II) and the catalytic activity of newly synthesized complexes have been studied. The complexes [RuCl(CO)(PPh3)2(L1)] (1), [RuCl(CO)(AsPh3)2(L1)] (2), [RuCl(CO)(PPh3)2(L2)] (3) and [RuCl(CO)(AsPh3)2(L2)] (4) were synthesized by reactions of [RuHCl(CO)(EPh3)3] (E = P or As) precursors with hydrazone ligands and characterized by analytical and spectroscopic methods. The molecular structure of complex 2 was identified by means of single-crystal X-ray diffraction analysis. The structural analysis revealed that all the complexes possess a distorted octahedral geometry with the ligand coordinating in a uni-negative bidentate NO fashion. Further, the catalytic efficiency of the complexes have been investigated in the case of direct amidation of alcohols with amines. The influence of base, reaction temperature and catalyst loading in the amidation reaction was also evaluated. Notably, complex 3 was found to be very efficient catalyst towards amidation of alcohols with amine. A variety of aromatic (hetero) amines and alcohols with various functional groups have also been successfully used for amidations.
- Selvamurugan, Sellappan,Ramachandran, Rangasamy,Prakash, Govindan,Viswanathamurthi, Periasamy,Malecki, Jan Grzegorz,Endo, Akira
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p. 119 - 127
(2015/12/30)
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- Ultrasound-assisted, convenient and widely applicable 1,1′-carbonyl-diimidazole-mediated "One-pot" syntheses of acyl/sulfonyl hydrazines
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Acyl / sulfonyl hydrazines were synthesized in a one-pot reaction from carboxylic acid/aryl sulfonic acid in the presence of 1,1′-carbonyl diimidazole (CDI) under ultrasound as well as under conventional heating. The reaction was performed on diverse organic molecules including simple benzoic acid (1), electron-donating and electron-withdrawing substituted benzoic acids, biologically active compounds like coumarin-3-carboxylic acid (12), 7-hydroxycoumarin-4-acetic acid (13), and therapeutic drugs like ibuprofen (14), flurbiprofen (15), naproxen (16) or tricyclic adamantane carboxylic acid (17). Benzene sulfonic acid (18) and its derivatives (19, 20, 21 and 22) were used to prepare corresponding sulfonyl hydrazide. All products were synthesized in very good yield via ultrasonic irradiation method and characterized by spectroscopic techniques including EIMS, 1H NMR, 13C NMR, IR. The method was found very simple, facile, efficient and high yielding (>90).
- Khan, Khalid Mohammed,Salar, Uzma,Fakhri, Muhammad Imran,Taha, Muhammad,Hameed, Abdul,Perveen, Shahnaz,Voelter, Wolfgang
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p. 637 - 644
(2015/11/09)
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- SAR studies on 1,2,4-triazolo[3,4-b][1,3,4]thiadiazoles as inhibitors of Mtb shikimate dehydrogenase for the development of novel antitubercular agents
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Shikimate dehydrogenase, an essential protein for the biosynthesis of the chorismate end product, is a highly promising therapeutic target, especially for the discovery and development of new-generation anti-TB agents. Following up the identification of one lead 3,6-disubstituted 1,2,4-triazolo[3,4-b][1,3,4]thiadiazole (1), targeting Mt SD in our previous study, an extensive SAR study for optimization of the lead compound was performed through systematic modification of the 3 and 6 positions. This study has successfully led to the discovery of two highly potent advanced leads 6d-4, 6c-4 and several other compounds with comparable potencies (6d-4, MIC-H37Rv = 0.5 μg mL-1; MIC-MDRTB = 4.0 μg mL-1; MIC-RDRTB = 0.5 μg mL-1; Mt SD-IC50 = 14.20 μg mL-1; and 6c-4, MIC-H37Rv = 0.5 μg mL-1; MIC-MDRTB = 4.0 μg mL-1; MIC-RDRTB = 1.0 μg mL-1; Mt SD-IC50 = 6.82 μg mL-1). These advanced lead compounds possess a para-halogen phenyl at the 3 position. In vitro Mt SD inhibitory assay indicates that Mt SD is the target for their antitubercular activity. Moreover, the BacT/ALERT 3D liquid culture technology and in vitro Mt SD inhibitory assay were initially applied.
- Li, Ziqiang,Liu, Yishuang,Bai, Xiaoguang,Deng, Qi,Wang, Juxian,Zhang, Guoning,Xiao, Chunling,Mei, Yaning,Wang, Yucheng
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p. 97089 - 97101
(2015/12/01)
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- Direct synthesis of amides from coupling of alcohols and amines catalyzed by ruthenium(II) thiocarboxamide complexes under aerobic conditions
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Four octahedral ruthenium(II) thiocarboxamide complexes of the general formula [RuClCO(AsPh3)2(L)] (L = N-substituted pyridine-2-thiocarboxamide) incorporating carbonyl and triphenylarsine have been synthesized from the reaction of 1 equiv of ruthenium precursor [RuHClCO(AsPh3)3] with 1 equiv of thiocarboxamide ligands in refluxing ethanol in the presence of base. All the new complexes have been fully characterized by means of elemental analysis, IR, UV-vis, and NMR spectral methods. Molecular structures of all the complexes were determined by X-ray crystallography, which confirm the coordination mode of thiocarboxamide and reveal the presence of a distorted octahedral geometry around the Ru ion. All the ruthenium(II) thiocarboxamide complexes were generated as highly efficient catalysts for synthesis of secondary or tertiary amides by coupling of amines and alcohols with low catalyst loading, and the maximum yield was obtained up to 97%. The coupling reaction can be readily carried out under mild aerobic conditions, and release of water is the only byproduct. Further, the effect of substituents of the ligand, solvents, reaction temperature, time, and catalyst loading on the catalytic activity of the complexes has been investigated. A plausible mechanism is proposed for the synthesis of amides via hemiaminal as intermediate through an oxidation of an alcohol to aldehyde.
- Sindhuja, Elangovan,Ramesh, Rengan,Balaji, Sundarraman,Liu, Yu
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p. 4269 - 4278
(2014/12/09)
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- A novel method for the conversion of carboxylic acids to N,N-dimethylamides using N,N-dimethylacetamide as a dimethylamine source
-
A simple, cost effective and environmentally benign method is reported for the preparation of N,N-dimethylamides from carboxylic acids. The versatility of the method is determined by synthesising a large number of N,N-dimethylamide derivatives. Carboxylic acids are heated at 160-165°C in N,N-dimethylacetamide solvent in the presence of1,1'-carbonyldiimidazole to afford the corresponding N,N-dimethylamides in good to excellent yields.
- Aavula, Sanjeev Kumar,Chikkulapally, Anil,Hanumanthappa,Jyothi, Indira,Vinod,Sulur, Kumar,Manjunatha,Sythana, Suresh Kumar
-
p. 155 - 159
(2013/07/11)
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- Bortezomib congeners induce apoptosis of hepatocellular carcinoma via CIP2A inhibition
-
CIP2A is an oncoprotein that upregulates p-Akt and promotes cancer cell proliferation and survival. The proteasome inhibitor bortezomib has been shown to reduce CIP2A and lead to cell apoptosis. Here; we modified the functional group of bortezomib to generate a series of novel compounds and conducted a structure-activity relationship (SAR) study. The results showed that compound 1 was able to repress CIP2A expression and cell apoptosis in the same manner as bortezomib, but with less potency in inhibition of proteasome activity. This finding provides a new direction for the design of CIP2A inhibitors.
- Hou, Duen-Ren,Huang, Ann-Chi,Shiau, Chung-Wai,Wang, Chun-Yi,Yu, Hui-Chuan,Chen, Kuen-Feng
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p. 15398 - 15411
(2014/01/17)
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- Microwave-assisted synthesis of 3-nitroindoles from N-aryl enamines via intramolecular arene-alkene coupling
-
A variety of N-aryl β-nitroenamines were effectively transformed into 3-nitroindoles in good yields and with complete regioselectivity via a rapid microwave (μW) assisted intramolecular arene-alkene coupling reaction. This report further demonstrates the versatility of this method by constructing 3-carboalkoxy-and 3-cyanoindoles. Optimization data, substrate scope, and applications are discussed.
- Nguyen, Huy H.,Kurth, Mark J.
-
supporting information
p. 362 - 365
(2013/03/13)
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- CDI-mediated monoacylation of symmetrical diamines and selective acylation of primary amines of unsymmetrical diamines
-
A highly efficient and green protocol for monoacylation of symmetrical diamines and chemoselective acylation of primary amines of unsymmetrical diamines has been developed.
- Verma, Sanjeev K.,Ghorpade, Ramarao,Pratap, Ajay,Kaushik
-
experimental part
p. 326 - 329
(2012/04/10)
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- Novel 5-substituted 1H-tetrazoles as cyclooxygenase-2 (COX-2) inhibitors
-
A series of novel 5-substituted 1H-tetrazoles as cyclooxygenase-2 (COX-2) inhibitors was prepared via treatment of various diaryl amides with tetrachlorosilane/sodium azide. All compounds were tested in cyclooxygenase (COX) assays in vitro to determine COX-1 and COX-2 inhibitory potency and selectivity. Tetrazoles contained a methylsulfonyl or sulfonamide group as COX-2 pharmacophore displayed only low inhibitory potency towards COX-2. Most potent compounds showed IC50 values of 6 and 7 μM for COX-2. All compounds showed IC50 values greater 100 μM for COX-1 inhibition.
- Al-Hourani, Baker Jawabrah,Sharma, Sai Kiran,Suresh, Mavanur,Wuest, Frank
-
supporting information; experimental part
p. 2235 - 2238
(2012/04/18)
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- Solvent free, N,N'-carbonyldiimidazole (CDI) mediated amidation
-
The method involves CDI mediated amidation under solvent-free conditions. The protocol is green, simple, and scalable and has broad structural applicability. The protocol has also been used for BOC protection of amine. The protocol has reduced the time for CDI mediated amidation from 2-4 h to 5-10 min without the use of any dry organic solvent and nitrogen atmosphere.
- Verma, Sanjeev K.,Ghorpade, Ramarao,Pratap, Ajay,Kaushik
-
experimental part
p. 2373 - 2376
(2012/05/31)
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- [Pd(μ-Br)(PtBu3)]2 as a highly active isomerization catalyst: Synthesis of enol esters from allylic esters
-
The dimeric Pd(I)-complex [Pd(μ-Br)(PtBu3)] 2 was found to be highly active for catalyzing double-bond migration in various substrates such as unsaturated ethers, alcohols, amides, and arenes, under mild conditions. It efficiently mediates the conversion of allylic esters into enol esters, rather than inserting into the allylic C-O bond. The broad applicability of this reaction was demonstrated with the synthesis of 22 functionalized enol esters.
- Mamone, Patrizia,Gruenberg, Matthias F.,Fromm, Andreas,Khan, Bilal A.,Goossen, Lukas J.
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supporting information; experimental part
p. 3716 - 3719
(2012/09/08)
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- Asymmetric Rh(II)-catalyzed cyclopropanation of alkenes with diacceptor diazo compounds: P -methoxyphenyl ketone as a general stereoselectivity controlling group
-
Different diacceptor diazo compounds bearing an α-PMP-ketone group were found to be effective carbene precursors for the highly stereoselective Rh2(S-TCPTTL)4-catalyzed cyclopropanation of alkenes (EWG = NO2, CN, CO2Me). The resulting products were readily transformed into a variety of biologically relevant enantiopure molecules, such as cyclopropane α- and β-amino acid derivatives. Different mechanistic studies carried out led to a rationale for the high diastereo- and enantioselectivity obtained, where the PMP-ketone moiety was found to play a critical role in the stereoinduction process. Additionally, the use of catalytic amounts of achiral Lewis bases to influence the enantioinduction of the reactions developed is documented.
- Lindsay, Vincent N. G.,Nicolas, Cyril,Charette, Andre B.
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supporting information; experimental part
p. 8972 - 8981
(2011/08/04)
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- Efficient synthesis of primary amides from carboxylic acids using n,n'-carbonyldiimidazole and ammonium acetate in ionic liquid
-
A novel and efficient method for the conversion of carboxylic acids to primary amides using N,N'-carbonyldiimidazole in combination with ammonium acetate/triethyl amine system in [BMIM]BF4 is developed.
- Lee, Kwan Soo,Kim, Kee D.
-
experimental part
p. 3497 - 3500
(2011/09/30)
-
- Discovery of Benzamide Analogues as a Novel Class of 5-HT3 Receptor Agonists
-
A 5-HT3 receptor agonist based on a benzamide scaffold was identified in a screening of a small commercial compound library, and an elaborate SAR study originating from this hit was performed. The design, synthesis, and functional characterisation of benzamide analogues at the 5-HT3A receptor yielded substantial information concerning the analogues as 5-HT3 receptor agonists. However, the potencies of the derived analogues were not significantly improved over that of the initial hit. The benzamide scaffold constitutes a novel type of 5-HT3 receptor agonist, as it does not possess a positively charged functionality, which is essential for the binding of all orthosteric ligands to the receptor. Preliminary investigations suggest that the compounds may exert their effects on 5-HT3 receptors by binding to an allosteric site in the receptor complex.
- Jorgensen, Charlotte G.,Frolund, Bente,Kehler, Jan,Jensen, Anders A.
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scheme or table
p. 725 - 736
(2012/01/06)
-
- Development and application of a solution-phase automated synthesizer, 'ChemKonzert'
-
In this paper we describe the development of a fully-automated solution-phase synthesizer, 'ChemKonzert' that can be used to prepare a wide variety of organic compounds. The automated synthesizer is ingeniously designed to perform most of the chemical reactions currently used by synthetic organic chemists and utilizes a centrifugal separator to efficiently achieve liquid-liquid extraction. The design of the hardware and software will be described in this paper, and several examples of organic reactions will also be presented as applications of the apparatus.
- Machida, Kazuhiro,Hirose, Yoichiro,Fuse, Shinichiro,Sugawara, Tohru,Takahashi, Takashi
-
experimental part
p. 87 - 93
(2010/04/05)
-
- Imidazole-catalyzed monoacylation of symmetrical diamines
-
Figure Presented. An imidazole-catalyzed protocol for monoacylation of symmetrical diamines has been developed. The protocol gave selective monoacylation of aliphatic (cyclic and acyclic) primary and secondary diamines. In the reaction, imidazole acts as both catalyst and a leaving group. Different monoacylated piperazines and other diamines were synthesized at room temperature in an ethanol/water solvent system.
- Verma, Sanjeev K.,Acharya,Kaushik
-
supporting information; experimental part
p. 4232 - 4235
(2010/11/04)
-
- Expedient synthesis of 3-hydroxyisoquinolines and 2-hydroxy-1,4- naphthoquinones via one-pot aryne acyl-alkylation/condensation
-
A convenient method is disclosed for the synthesis of both 3-hydroxyisoquinolines and 2-hydroxy-1,4-naphthoquinones from β-ketoesters using a one-pot aryne acyl-alkylation/condensation procedure. When performed in conjunction with a one-step method for the synthesis of the β-ketoester substrates, this method provides a new route to these polyaromatic structures in only two steps from commercially available carboxylic acid starting materials. The utility of this approach is demonstrated in the synthesis of the atropisomeric P,N-ligand, QUINAP. The Royal Society of Chemistry 2009.
- Allan, Kevin M.,Hong, Boram D.,Stoltz, Brian M.
-
supporting information; experimental part
p. 4960 - 4964
(2010/02/15)
-
- N,N-carbonyldiimidazole-mediated amide coupling: Significant rate enhancement achieved by acid catalysis with imidazole - HCI
-
Over a series of 10 aromatic amines we show the rate of CDI mediated amidation to be significantly enhanced upon introduction of imidazole·HCI as a proton source for acid catalysis. Our work supports and provides an application for previous investigations into the imidazolium effect, thus increasing the scope of CDI as an amide-coupling reagent with aromatic amines. The influence of the relative pKa of the amines studied on the rate of reaction was also investigated.
- Woodman, Emily K.,Chaffey, Julian G. K.,Hopes, Philip A.,Hose, David R. J.,Gilday, John P.
-
experimental part
p. 106 - 113
(2010/04/22)
-
- Absolute configuration of the α,ω-bifunctionalized sphingolipid leucettamol a from leucetta microrhaphis by deconvoluted exciton coupled CD
-
The configuration of leucettamol A (1), a known long-chain "two-headed" sphingolipid (dimeric sphingolipid) from the marine sponge Leucetta microrhaphis, was determined by conversion to an N, N', O, O'-tetrabenzoyl derivative, measurement of the exciton coupled circular dichroism spectrum (ECCD), and quantitative analysis by deconvolution of superposed exciton couplets. Contrary to the earlier assignment that claimed leucettamol A (1) was racemic, the CD approach unambiguously reveals the natural product is chiral and optically active and displays pseudo-C2 symmetry. The configuration of each end of the chain has erythro stereochemistry with an absolute configuration of 2R,3S,28S,29R. We show that deconvolution ECCD reliably predicts erythro versus threo vicinal amino alcohols in all cases with greater sensitivity (1H NMR J-based methods and provides verification of optical purity and unequivocal elucidation of absolute configuration in this difficult class of natural products.
- Dalisay, Doralyn S.,Tsukamoto, Sachiko,Molinski, Tadeusz F.
-
experimental part
p. 353 - 359
(2009/12/05)
-
- Indium-mediated one-pot synthesis of benzoxazoles or oxazoles from 2-nitrophenols or 1-aryl-2-nitroethanones
-
One-pot reduction-triggered heterocyclizations from 2-nitrophenols to benzoxazoles and from 1-aryl-2-nitroethanones to oxazoles were investigated. In the presence of indium/AcOH in benzene at reflux, 2-nitrophenols and R-C(OMe)3 (R=H, Me, Ph) produced excellent yields of corresponding benzoxazoles within an hour. Similarly, 1-aryl-2-nitroethanones and Ph-C(OMe)3 in the presence of indium/AcOH in acetonitrile transformed into the corresponding oxazoles with good yields.
- Lee, Jung June,Kim, Jihye,Jun, Young Moo,Lee, Byung Min,Kim, Byeong Hyo
-
experimental part
p. 8821 - 8831
(2009/12/26)
-
- Acylguanidines as bioisosteres of guanidines: NG-acylated imidazolylpropylguanidines, a new class of histamine h2 receptor agonists
-
N1-Aryl(heteroaryl)alkyl-N2-[3-(1H-imidazol-4-yl) propyl]guanidines are potent histamine H2-receptor (H2R) agonists, but their applicability is compromised by the lack of oral bioavailability and CNS penetration. To improve pharmacokinetics, we introduced carbonyl instead of methylene adjacent to the guanidine moiety, decreasing the basicity of the novel H2R agonists by 4-5 orders of magnitude. Some acylguanidines with one phenyl ring were even more potent than their diaryl analogues. As demonstrated by HPLC-MS, the acylguanidines (bioisosteres of the alkylguanidines) were absorbed from the gut of mice and detected in brain. In GTPase assays using recombinant receptors, acylguanidines were more potent at the guinea pig than at the human H2R. At the hH1R and hH3R, the compounds were weak to moderate antagonists or partial agonists. Moreover, potent partial hH4R agonists were identified. Receptor subtype selectivity depends on the imidazolylpropylguanidine moiety (privileged structure), opening an avenue to distinct pharmacological tools including potent H4R agonists.
- Ghorai, Prasanta,Kraus, Anja,Keller, Max,G?tte, Carsten,Igel, Patrick,Schneider, Erich,Schnell, David,Bernhardt, Günther,Dove, Stefan,Zabel, Manfred,Elz, Sigurd,Seifert, Roland,Buschauer, Armin
-
supporting information; experimental part
p. 7193 - 7204
(2009/10/02)
-
- Microwave-assisted synthesis of amides from various amines and benzoyl chloride under solvent-free conditions: A rapid and efficient method for selective protection of diverse amines
-
A number of structurally diverse amides were synthesized by reaction of the corresponding amines with benzoyl chloride under microwave irradiation. The proposed procedure ensures short reaction time, high yields, and excellent selectivity and considerably broadens the series of amines as compared to the microwave-assisted synthesis of amides directly from carboxylic acids. It can also be used for selective protection of various amines, including aromatic, aliphatic, and heterocyclic.
- Li, Yanqiu,Wang, Yulu,Wang, Jinye
-
p. 358 - 361
(2008/12/22)
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- Asymmetric Michael addition of α-nitro-ketones using catalytic peptides
-
Peptide-based catalysts have been developed that promote the asymmetric Michael addition of nitroalkanes. The most effective peptides contain a β-turn structural element as well as a basic histidine and an arylsulfonamide-protected arginine. Excellent yields with enantioselectivities of up to 74% ee have been observed.
- Linton, Brian R.,Reutershan, Michael H.,Aderman, Christopher M.,Richardson, Elizabeth A.,Brownell, Kristen R.,Ashley, Charles W.,Evans, Catherine A.,Miller, Scott J.
-
p. 1993 - 1997
(2007/10/03)
-
- One-pot conversion of a representative series of carboxylic acids to the corresponding methyl ketones
-
The use of imidazolide activation method for direct acylation of Meldrum's acid with carboxylic acids, and the subsequent acidic hydrolysis of the acylated products to methyl ketones, provide a simple and efficient method for a one-pot conversion of carboxylic acids to the corresponding methyl ketones.
- Hamilakis, Stylianos,Tsolomitis, Athanase
-
p. 149 - 152
(2007/10/03)
-
- Kinetic and structural consequences of the leaving group in substrates of a class C β-lactamase
-
The class C β-lactamase of Enterobacter cloacae P99 is known to catalyze the hydrolysis of certain acyclic (thio)esters. Previous experiments have employed thioglycolate, m-hydroxybenzoate, and phenylphosphate leaving groups. The relative effectiveness of these leaving groups has now been quantitatively assessed by employment of a series of compounds with common acyl groups, and found to rank in the order phenylphosphate >m-hydroxybenzoate >thioglycolate. Structural models suggest that these leaving groups interact during acylation principally with Tyr 150, Lys 315, and Thr 316 of the β-lactamase active site. The positions of the leaving group carboxylates in these models is compared with those in published crystal structures of complexes of class C β-lactamases with β-lactams. The particular effectiveness of the acyl phosphate indicates the positions of two oxyanions that strongly interact with the active site. This information should be useful in the design of inhibitors of class C β-lactamases.
- Ahn, Yong-Mo,Pratt
-
p. 1537 - 1542
(2007/10/03)
-
- Novel quinolinone-phosphonic acid AMPA antagonists devoid of nephrotoxicity.
-
We reported previously the synthesis and structure-activity relationships (SAR) in a series of 2-(1H)-oxoquinolines bearing different acidic functions in the 3-position. Exploiting these SAR, we were able to identify 6,7-dichloro-2-(1H)-oxoquinoline-3-phosphonic acid compound 3 (S 17625) as a potent, in vivo active AMPA antagonist. Unfortunately, during the course of the development, nephrotoxicity was manifest at therapeutically effective doses. Considering that some similitude exists between S 17625 and probenecid, a compound known to protect against the nephrotoxicity and/or slow the clearance of different drugs, we decided to synthesise some new analogues of S 17625 incorporating some of the salient features of probenecid. Replacement of the chlorine in position 6 by a sulfonylamine led to very potent AMPA antagonists endowed with good in vivo activity and lacking nephrotoxicity potential. Amongst the compounds evaluated, derivatives 7a and 7s appear to be the most promising and are currently evaluated in therapeutically relevant stroke models.
- Cordi, Alex A,Desos, Patrice,Ruano, Elisabeth,Al-Badri, Hashim,Fugier, Claude,Chapman, Astrid G,Meldrum, Brian S,Thomas, Jean-Yves,Roger, Anita,Lestage, Pierre
-
p. 787 - 802
(2007/10/03)
-
- Synthesis of S-thioacyl dithiophosphates, efficient and chemoselective thioacylating agents
-
Easily available acyl dithiophosphates are not stable and isomerise reversibly to O-thioacyl monothiophosphates, especially when subjected to heating. Much slower but probably irreversible isomerisation to S-thioacyl monothiophosphates occurs. Since equilibrium states are established and S-thioacyl (mono)thiophosphates form slowly, reaction mixtures contain generally both thioacylating and acylating agents, and consequently cannot be used for efficient thioacylation. On the other hand, treatment of a mixture of isomeric anhydrides with an excess of a dithiophosphoric acid leads to exclusive formation of S-thioacyl dithiophosphates. They appear to be excellent thioacylating agents: relatively stable, inert towards water and oxygen and therefore easy to handle. Reactions with nitrogen or sulfur nucleophiles proceed very rapidly under ambient conditions, yielding respective thioacyl derivatives. Isolation of the products is very simple. Due to the low reactivity of S-thioacyl dithiophosphates towards oxygen nucleophiles they can be used for direct thioacylation of multifunctional nucleophiles with unprotected hydroxy groups. Respective thioacyl derivatives cannot readily be obtained using other methods.
- Doszczak, Leszek,Rachon, Janusz
-
p. 1271 - 1279
(2007/10/03)
-
