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
Formal [3 + 4] Annulation of α,β-Unsaturated Acyl Azoliums: Access to Enantioenriched N–<i>H</i>-Free 1,5-Benzothiazepines
作者:Chao Fang、Tao Lu、Jindong Zhu、Kewen Sun、Ding Du
DOI:10.1021/acs.orglett.7b01457
日期:2017.7.7
An unprecedented formal [3 + 4] annulation of α,β-unsaturatedacyl azoliums with 2-aminobenzenethiols has been utilized to synthesize enantioenriched N–H-free 1,5-benzothiazepines, which are recognized as privileged structures in numerous biologically active scaffolds. This protocol offers a rapid and direct pathway to access the target compounds with high enantioselectivities and has been applied