NBS / DMSO介导的由芳氧基甲基噻喃合成(2,3-二氢苯并[ b ] [1,4]草酰-3-基)甲醇†
摘要:
通过芳氧基甲基硫烷和N-溴琥珀酰亚胺(NBS)在DMSO下微波辐射反应合成了(2,3-二氢苯并[ b ] [1,4]氧杂嘧啶-3-基)甲醇。该反应机理被认为是由芳氧基甲基噻喃和NBS生成的1-溴-2-(芳氧基甲基)噻喃-1-鎓的分子内芳族亲电取代,以及随后的噻吩-1-鎓的DMSO亲核开环反应,随后是排水量。当前的方法提供了一种直接和简单的策略,可以从容易获得的芳氧基甲基噻喃有效地制备(2,3-二氢苯并[ b ] [1,4]氧杂蒽-3-基)甲醇。
Biocatalytic Thionation of Epoxides for Enantioselective Synthesis of Thiiranes
作者:Ran Ma、Xia Hua、Cheng‐Li He、Hui‐Hui Wang、Zhu‐Xiang Wang、Bao‐Dong Cui、Wen‐Yong Han、Yong‐Zheng Chen、Nan‐Wei Wan
DOI:10.1002/anie.202212589
日期:2022.12.23
A biocatalytic thionation method is presented for the enantioselective synthesis of thiiranes from epoxides by a halohydrin dehalogenase catalyzed kinetic resolution approach using thiocyanate as a sulfur donor. Various chiral thiiranes bearing aryl and alkyl substituents were synthesized in good yields and enantioselectivities by using recombinant Escherichia coli cells expressing the engineered halohydrin
A simple and efficient method for the conversion of oxiranes to thiiranes using ammonium thiocyanate (NH4SCN) under solvent- and catalyst-free conditions is described. These conditions enable clean and fast conversion of oxiranes to the corresponding thiirane.