97-71-2Relevant articles and documents
Electrochemical Ring-Opening Dicarboxylation of Strained Carbon-Carbon Single Bonds with CO2: Facile Synthesis of Diacids and Derivatization into Polyesters
Liao, Li-Li,Wang, Zhe-Hao,Cao, Ke-Gong,Sun, Guo-Quan,Zhang, Wei,Ran, Chuan-Kun,Li, Yiwen,Chen, Li,Cao, Guang-Mei,Yu, Da-Gang
supporting information, p. 2062 - 2068 (2022/02/10)
Diacids are important monomers in the polymer industry to construct valuable materials. Dicarboxylation of unsaturated bonds, such as alkenes and alkynes, with CO2 has been demonstrated as a promising synthetic method. However, dicarboxylation of C-C single bonds with CO2 has rarely been investigated. Herein we report a novel electrochemical ring-opening dicarboxylation of C-C single bonds in strained rings with CO2. Structurally diverse glutaric acid and adipic acid derivatives were synthesized from substituted cyclopropanes and cyclobutanes in moderate to high yields. In contrast to oxidative ring openings, this is also the first realization of an electroreductive ring-opening reaction of strained rings, including commercialized ones. Control experiments suggested that radical anions and carbanions might be the key intermediates in this reaction. Moreover, this process features high step and atom economy, mild reaction conditions (1 atm, room temperature), good chemoselectivity and functional group tolerance, low electrolyte concentration, and easy derivatization of the products. Furthermore, we conducted polymerization of the corresponding diesters with diols to obtain a potential UV-shielding material with a self-healing function and a fluorine-containing polyester, whose performance tests showed promising applications.
Synthesis of ruthenium–dithiocarbamate chelates bearing diphosphine ligands and their use as latent initiators for atom transfer radical additions
Aldin, Mohammed Zain,Delaude, Lionel,Zaragoza, Guillermo
supporting information, (2021/08/03)
Nine representative [Ru(S2CNEt2)2(diphos)] complexes were prepared in almost quantitative yields (91–97%) from [RuCl2(p-cymene)]2, sodium diethyldithiocarbamate trihydrate, and a diphosphine (dppm, dppe, dppp, dppb, dpppe, dppen, dppbz, dppf, or DPEphos), using a novel, straightforward, one-pot procedure. The recourse to a monomodal microwave reactor was instrumental in reaching the thermodynamic equilibria favoring the targeted monometallic trichelates. All the products were fully characterized by using various analytical techniques and the molecular structures of seven of them were determined by X-ray crystallography. NMR, XRD, and IR spectroscopies evidenced a significant contribution of the thioureide resonance form Et2N+=CS22– to the electronic structure of the 1,1-dithiolate ligand. MS/MS spectrometry showed the formation of phosphine-free [Ru(S2CNEt2)2]+ cations in the gas phase, except when starting from [Ru(S2CNEt2)2(dppbz)]. The activity of the nine complexes was probed in three different catalytic processes, viz., the cyclopropanation of styrene with ethyl diazoacetate, the synthesis of vinyl esters from benzoic acid and 1-hexyne, and the atom transfer radical addition (ATRA) of carbon tetrachloride and methyl methacrylate. In the first two reactions, the saturated trichelates were poorly efficient. This was most likely due to their high stability, which prevented the formation of coordinatively unsaturated species. Contrastingly, with a turnover number of 2000 and an initial turnover frequency of 2080 h–1 for a 0.05 mol% catalyst loading, the [Ru(S2CNEt2)2(dppm)] complex emerged as a very robust, latent ATRA initiator, whose activity matched or outperformed those displayed by the most efficient ruthenium catalysts described so far.
Noncanonical Heme Ligands Steer Carbene Transfer Reactivity in an Artificial Metalloenzyme**
Dunkelmann, Daniel,Hayashi, Takahiro,Hilvert, Donald,Mittl, Peer R. E.,Ota, Yusuke,Pott, Moritz,Tinzl, Matthias
supporting information, p. 15063 - 15068 (2021/06/09)
Changing the primary metal coordination sphere is a powerful strategy for tuning metalloprotein properties. Here we used amber stop codon suppression with engineered pyrrolysyl-tRNA synthetases, including two newly evolved enzymes, to replace the proximal histidine in myoglobin with Nδ-methylhistidine, 5-thiazoylalanine, 4-thiazoylalanine and 3-(3-thienyl)alanine. In addition to tuning the heme redox potential over a >200 mV range, these noncanonical ligands modulate the protein's carbene transfer activity with ethyl diazoacetate. Variants with increased reduction potential proved superior for cyclopropanation and N–H insertion, whereas variants with reduced Eo values gave higher S–H insertion activity. Given the functional importance of histidine in many enzymes, these genetically encoded analogues could be valuable tools for probing mechanism and enabling new chemistries.
