Catalytic Enantioselective Synthesis of Protecting-Group-Free 1,5-Benzothiazepines
作者:Sara Meninno、Chiara Volpe、Alessandra Lattanzi
DOI:10.1002/chem.201700837
日期:2017.4.3
2,3‐dihydro‐1,5‐benzothiazepinones, by an organocatalyzed sulfa‐Michael reaction of readily available α,β‐unsaturated N‐acyl pyrazoles with 2‐aminothiophenols followed by silica‐gel‐catalyzed lactamization, has been developed. The method proceeds under mild conditions at room temperature and it requires only 1 mol % catalyst loading, to give 2‐aryl/alkyl‐substituted 1,5‐benzothiazepines in generally
Enantioselective Michael addition reactions of malononitrile catalyzed by chiral Lewis acid and achiral amine catalysts
作者:Kennosuke Itoh、Yoji Oderaotoshi、Shuji Kanemasa
DOI:10.1016/s0957-4166(03)00084-3
日期:2003.3
Reactions of malononitrile with 3-(2-alkenoyl)-2-oxazolidinones or 1-(2-alkenoyl)-4-bromo-3,5-dimethylpyrazoles can be doubly activated by the use of catalytic amounts (10 mol% each) of both, (R,R)-DBFOX/Ph-Ni(ClO4)(2)(.)3H(2)O and amines, to give the Michael adducts in high chemical yields with satisfactory enantioselectivities. (C) 2003 Elsevier Science Ltd. All rights reserved.