Kinetic Resolution of 2-Oxazolidinones via Catalytic, Enantioselective N-Acylation
摘要:
Kinetic resolution of racemic 2-oxazolidinones via catalytic, enantioselective N-acylation has been achieved for the first time and with outstanding selectivities.
selectivity. trans-Oxazolidinones were prepared from acyclic secondary N-mesyloxycarbamates using Rh2(oct)4. The selectivity was reverted with a cytoxazone N-mesyloxycarbamate precursor using large chiralrhodium(II) carboxylate complexes, affording the corresponding cis-oxazolidinone. This orthogonal selectivity was used to achieve the formal synthesis of (−)-cytoxazone.
Catalytic, Enantioselective N-Acylation of Lactams and Thiolactams Using Amidine-Based Catalysts
作者:Xing Yang、Valentina D. Bumbu、Peng Liu、Ximin Li、Hui Jiang、Eric W. Uffman、Lei Guo、Wei Zhang、Xuntian Jiang、K. N. Houk、Vladimir B. Birman
DOI:10.1021/ja306766n
日期:2012.10.24
contrast to alcohols and amines, racemic lactams and thiolactams cannot be resolved directly via enzymatic acylation or classical resolution. Asymmetric N-acylation promoted by amidine-based catalysts, particularly Cl-PIQ 2 and BTM 3, provides a convenient method for the kinetic resolution of these valuable compounds and often achieves excellent levels of enantioselectivity in this process. Density
Herein, we report the development of a tailored cobalt catalyst system of Cp*Co(III)(LX) toward intramolecular C-H nitrene insertion of azidoformates to afford cyclic carbamates. The cobalt complexes were easy to prepare and bench-stable, thus offering a convenient reaction protocol. The catalytic reactivity was significantly improved by the electronic tuning of the bidentate LX ligands, and the observed
Kinetic Resolution of 2-Oxazolidinones via Catalytic, Enantioselective N-Acylation
作者:Vladimir B. Birman、Hui Jiang、Ximin Li、Lei Guo、Eric W. Uffman
DOI:10.1021/ja061560m
日期:2006.5.1
Kinetic resolution of racemic 2-oxazolidinones via catalytic, enantioselective N-acylation has been achieved for the first time and with outstanding selectivities.