291533-24-9Relevant academic research and scientific papers
Activation of (salen)CoI complex by phosphorane for carbon dioxide transformation at ambient temperature and pressure
Zhou, Feng,Xie, Shi-Liang,Gao, Xiao-Tong,Zhang, Rong,Wang, Cui-Hong,Yin, Guang-Qiang,Zhou, Jian
supporting information, p. 3908 - 3915 (2017/08/22)
We report the activation of (salen)CoI complex 3g by a phosphorane to form a bifunctional catalyst for the reaction of carbon dioxide with terminal epoxides or aziridines at ambient temperature and 1 bar carbon dioxide pressure. Only 1.0 mol% of both (salen)CoI 3g and phosphorane 4d are required for cyclic carbonate synthesis, and the catalyst loading could even be lowered down to 0.1 mol%. Under these conditions, no polycarbonate formation is detected by NMR analysis. It is proposed that the high efficiency originates from the activation of (salen)CoI by a phosphorane to form a phosphorane-salen Co(iii) complex with enhanced Lewis acidity for the electrophilic activation while generating an iodide anion as a Lewis base co-catalyst to facilitate the ring-opening of epoxides. Further investigation revealed that the phosphorane-(salen)CoI complex could also successfully catalyze the coupling of CO2 with aziridines under ambient conditions at a catalyst loading of 2.5 mol%.
Synthesis of chiral oxazolidinone derivatives through lipase-catalyzed kinetic resolution
Zhang, Yan,Zhang, Yang,Ren, Yansong,Ramstr?m, Olof
, p. 29 - 34 (2015/09/15)
The synthesis of enantioenriched oxazolidinone derivatives through lipase-catalyzed kinetic resolution is described. The synthesis comprised a two-step, cascade acylation in one pot, resulting in a range of oxazolidinone derivatives in good yields and exc
Solvent and in situ catalyst preparation impacts upon Noyori reductions of aryl-chloromethyl ketones: application to syntheses of chiral 2-amino-1-aryl-ethanols
Tanis, Steven P.,Evans, Bruce R.,Nieman, James A.,Parker, Timothy T.,Taylor, Wendy D.,Heasley, Steven E.,Herrinton, Paul M.,Perrault, William R.,Hohler, Richard A.,Dolak, Lester A.,Hester, Matthew R.,Seest, Eric P.
, p. 2154 - 2182 (2007/10/03)
As part of medicinal chemistry efforts we found it necessary to develop general syntheses of highly enantiomerically enriched 1-aryl-2-chloroethanols and 1-aryl-2-methylaminoethanols. A survey of literature methods suggested that a truly general approach had not yet been reported, encouraging us to undertake the development of such a methodology. This study describes the design, development, and reduction to practice of a general synthesis of chiral 1-aryl-2-chloroethanols and the transformation of these entities to highly enantiomerically enriched 1-aryl-2-methylaminoethanols. Of particular importance were observations of the impact of solvent and the method of catalyst preparation on the yield and enantiomerical excess of chlorohydrins prepared via Noyori transfer hydrogenations of aryl-chloromethyl ketones.
