An enantioselective sulfa‐Michael‐cyclization reaction was developed for the synthesis of 1,5‐benzothiazepines with versatile pharmacological activities. The reaction between 2‐aminothiophenol and α,β‐unsaturated pyrazoleamides gave direct access to N−H‐free 1,5‐benzothiazepines in the presence of a chiral N,N′‐dioxide/Yb(OTf)3 complex. Excellent enantioselectivities (up to 96 % ee) and high yields
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