- Functionalization of Alkenyl C-H Bonds with D 2 O via Pd(0)/Carboxylic Acid Catalysis
-
We report herein a simple catalytic method for the extensive labeling of alkenyl C-H bonds through the combination of a palladium(0) complex and a carboxylic acid in the presence of deuterium oxide. The reaction can be applied to a variety of terminal alkenes and the best results are obtained with aryl-substituted examples. This method represents a convenient approach for the preparation of extensively labeled chemicals from the cheapest and safest source of deuterium.
- Bigi, Franca,Camedda, Nicola,Cera, Gianpiero,Maestri, Giovanni,Maggi, Raimondo,Serafino, Andrea
-
supporting information
p. 1762 - 1772
(2020/06/08)
-
- Evaluation of Potential Safety Hazards Associated with the Suzuki-Miyaura Cross-Coupling of Aryl Bromides with Vinylboron Species
-
The potential safety hazards associated with the Suzuki-Miyaura cross-coupling of aryl bromides with vinylboron species were evaluated. In the Suzuki-Miyaura cross-coupling of 1-bromo-3-(trifluoromethyl)benzene with potassium vinyltrifluoroborate in the presence of potassium carbonate (K2CO3) in 9:1 dimethyl sulfoxide (DMSO)/water at 80 °C, the thermal profile revealed a significant exotherm upon the addition of catalytic 1,1′-bis(diphenylphosphino)ferrocene palladium(II) dichloride [Pd(dppf)Cl2]. Further investigations indicated that the exotherm was consistently higher and the reactions were faster in the studied aqueous systems compared to anhydrous conditions. Although under anhydrous conditions the exotherms were comparable among the studied cases, the rate of the exotherm was highly dependent on the choice of aryl electrophile, solvent, base, catalyst, as well as vinylboron species. In many of the studied cases the maximum temperature of a synthesis reaction (MTSR) was considerably higher than the boiling point of the solvent and/or the onset temperature of the DMSO decomposition, indicating that in the absence of active cooling the system could quickly exceed the boiling point of the solvent or trigger the decomposition of the reaction mixture to result in a runaway reaction.
- Yang, Qiang,Canturk, Belgin,Gray, Kaitlyn,McCusker, Elizabeth,Sheng, Min,Li, Fangzheng
-
p. 351 - 359
(2018/03/22)
-
- Synthesis of α-pyrones by catalytic oxidative coupling of terminal alkynes and carbon dioxide
-
The use of the complex [(dippe)Ni(μ-H)]2(1) as a catalyst precursor (10?mol%) in the presence of a variety of terminal alkynes and CO2allowed the production of substituted α–pyrones. This reaction occurs using relatively mild conditions (50?°C, 150 psi of CO2) with good to modest yields, depending on the nature of the substituents in the corresponding alkyne. The produced α–pyrones were characterized by different analytical methods and spectroscopic techniques.
- Oliveros-Cruz, Saray,Arévalo, Alma,García, Juventino J.
-
-
- Benzocarbazoles dioxane derivatives, its preparation process and its use in medicine
-
The invention relates to a benzodioxane derivative, a preparation method thereof and application of the derivative in medicines. Specifically, the invention relates to a novel benzodioxane derivative shown as a formula (I), medial salt thereof or a medicine composition containing the derivative, and a preparation method of the derivative. The invention further relates to a use of the benzodioxane derivative and the medial salt thereof or the medicine composition containing the derivative in preparing therapeutic agent, especially GPR 40 agonist, and a drug for treating the diseases such as diabetes, metabolic disorders and the like, wherein each substituent group in the formula (I) is as defined in the description.
- -
-
Paragraph 0801; 0804-0807
(2016/10/10)
-
- Structurally Defined Molecular Hypervalent Iodine Catalysts for Intermolecular Enantioselective Reactions
-
Molecular structures of the most prominent chiral non-racemic hypervalent iodine(III) reagents to date have been elucidated for the first time. The formation of a chirally induced supramolecular scaffold based on a selective hydrogen-bonding arrangement provides an explanation for the consistently high asymmetric induction with these reagents. As an exploratory example, their scope as chiral catalysts was extended to the enantioselective dioxygenation of alkenes. A series of terminal styrenes are converted into the corresponding vicinal diacetoxylation products under mild conditions and provide the proof of principle for a truly intermolecular asymmetric alkene oxidation under iodine(I/III) catalysis.
- Haubenreisser, Stefan,W?ste, Thorsten H.,Martnez, Claudio,Ishihara, Kazuaki,Muiz, Kilian
-
supporting information
p. 413 - 417
(2016/01/25)
-
- Oxidative trifluoromethylation and fluoroolefination of unactivated olefins
-
Fluorine-containing organic compounds are gaining increasing importance in medicinal chemistry. Described herein is a mild and efficient method for the radical addition of olefins with TMSCF3 and TMSCF2R (R = COOEt or CF3) to deliver various α-trifluoromethylated ketones and α-fluoroolefinated ketones.
- Wu, Ye-Bin,Lu, Guo-Ping,Yuan, Tao,Xu, Zhu-Bing,Wan, Li,Cai, Chun
-
supporting information
p. 13668 - 13670
(2016/11/29)
-
- Facile Protocol for Catalytic Frustrated Lewis Pair Hydrogenation and Reductive Deoxygenation of Ketones and Aldehydes
-
A series of ketones and aldehydes are reduced in toluene under H2 in the presence of 5 mol % B(C6F5)3 and either cyclodextrin or molecular sieves affording a facile metal-free protocol for reduction to alcohols. Similar treatment of aryl ketones resulted in metal-free deoxygenation yielding aromatic hydrocarbons.
- Mahdi, Tayseer,Stephan, Douglas W.
-
p. 8511 - 8514
(2015/11/27)
-
- Heck, Sonogashira, and Hiyama reactions catalyzed by palladium nanoparticles stabilized by tris-imidazolium salt
-
Palladium nanoparticles, prepared by the hydrogenation of Pd(dba) 2 in the presence of a tris-imidazolium iodide as stabilizer, act as an efficient catalyst for Heck and copper-free Sonogashira reactions with a range of aryl iodides and bromides at 0.2 mol-% Pd loading. Moreover, we describe a convenient protocol for the fluoride-free Hiyama coupling of vinylsilanes with aryl iodides that involves the use of sodium hydroxide as promoter in a methanol/water mixture. Under the developed conditions, one-pot, double Heck and Hiyama-Heck reactions are successfully achieved.
- Planellas, Marc,Moglie, Yanina,Alonso, Francisco,Yus, Miguel,Pleixats, Roser,Shafir, Alexandr
-
supporting information
p. 3001 - 3008
(2014/05/20)
-
- Isomerizing ethenolysis as an efficient strategy for styrene synthesis
-
A shrinking chain: A bimetallic system consisting of [{Pd(μ-Br)(tBu 3P)}2] and a ruthenium metathesis catalyst has been found to efficiently promote the cross-metathesis between substituted alkenes and ethylene, while continuously migrating the double bond along the alkenyl chain (see scheme). When alkenylarenes, such as the natural products eugenol, safrol, or estragol, were treated with this catalyst under an ethylene atmosphere, they were cleanly converted into the corresponding styrenes and propylene gas. Copyright
- Baader, Sabrina,Ohlmann, Dominik M.,Goossen, Lukas J.
-
p. 9807 - 9810
(2013/08/23)
-
- SUBSTITUTED HETEROCYCLIC ACETAMIDES AS KAPPA OPIOID RECEPTOR (KOR) AGONISTS
-
The present invention relates to a series of substituted compounds having the general formula (I), including their ste reoisomers and/or their pharmaceutically acceptable salts, wherein R1, R2, R3. R4, R5, and R6 are as defined herein. This invention also relates to methods of making these compounds including intermediates. The compounds of this invention are effective at the kappa (κ) opioid receptor (KOR) site. Therefore, the compounds of this invention are useful as pharmaceutical agents, especially in the treatment and/or prevention of a variety of central nervous system disorders (CNS), including but not limited to acute and chronic pain, and associated disorders, particularly functioning peripherally at the CNS.
- -
-
Page/Page column 116
(2013/09/26)
-
- α-Selective Ni-catalyzed hydroalumination of aryl- and alkyl-substituted terminal alkynes: Practical syntheses of internal vinyl aluminums, halides, or boronates
-
A method for Ni-catalyzed hydroalumination of terminal alkynes, leading to the formation of α-vinylaluminum isomers efficiently (>98% conv in 2-12 h) and with high selectivity (95% to >98% α), is described. Catalytic α-selective hydroalumination reactions proceed in the presence of a reagent (diisobutylaluminum hydride; dibal-H) and 3.0 mol % metal complex (Ni(dppp)Cl2) that are commercially available and inexpensive. Under the same conditions, but with Ni(PPh3)2Cl2, hydroalumination becomes highly β-selective, and, unlike uncatalyzed transformations with dibal-H, generates little or no alkynylaluminum byproducts. All hydrometalation reactions are reliable, operationally simple, and practical and afford an assortment of vinylaluminums that are otherwise not easily accessible. The derived α-vinyl halides and boronates can be synthesized through direct treatment with the appropriate electrophiles [e.g., Br 2 and methoxy(pinacolato)boron, respectively]. Ni-catalyzed hydroaluminations can be performed with as little as 0.1 mol % catalyst and on gram scale with equally high efficiency and selectivity.
- Gao, Fang,Hoveyda, Amir H.
-
supporting information; experimental part
p. 10961 - 10963
(2010/09/17)
-
- Choix des methodes pour la synthese univoque de carbures acetyleniques. Troisieme partie : Arylacetylenes et aryl-1 alcynes-1
-
The range of applicability of six syntheses of pure alkynes with one aryl group has been defined; a short review of other possible procedures is included.We have specified the best method to obtain selectively the alkynes Ar-CCH and Ar-CC-R, according to the nature of the substituents of the aryl group and according to the developed structure of the R group.It is thus possible to recommend with the largest probability of success the method to obtain, in homogenous series, alkynes corresponding to still more complicated structures.
- Mesnard, Danielle,Bernadou, Francoise,Miginiac, Leone
-
p. 3216 - 3245
(2007/10/02)
-
