Gleason-type chiralauxiliaries were used for the synthesis of a novel class of sulfonium salts, obtained via methylation of the sulfide with Meerwein's salt. The salts were reacted with aldehydes under basic conditions to provide epoxy amides, which were reduced to their corresponding epoxy alcohols in excellent enantiomeric excesses. Interestingly, it was feasible to synthesize both enantiomeric
A new type of chiral sulfur ylides has been synthesized and their reactivities against carbonyl compounds tested, showing a high degree of stereoselectivity in the formation of transepoxyamides under very mild reaction conditions.
Enantiocomplementary Epoxidation Reactions Catalyzed by an Engineered Cofactor‐Independent Non‐natural Peroxygenase
作者:Guangcai Xu、Michele Crotti、Thangavelu Saravanan、Kim M. Kataja、Gerrit J. Poelarends
DOI:10.1002/anie.202001373
日期:2020.6.22
heme‐dependent enzymes that use peroxide‐borne oxygen to catalyze a wide range of oxyfunctionalization reactions. Herein, we report the engineering of an unusual cofactor‐independent peroxygenase based on a promiscuous tautomerase that accepts different hydroperoxides (t ‐BuOOH and H2O2) to accomplish enantiocomplementary epoxidations of various α,β‐unsaturated aldehydes (citral and substituted cinnamaldehydes)
过氧合酶是血红素依赖性酶,它使用过氧化物所携带的氧来催化广泛的氧官能化反应。本文中,我们报道了一种基于互变互变异构酶的不寻常辅酶非依赖性过氧化酶的工程改造,该互变异构酶接受不同的氢过氧化物(t- BuOOH和H 2 O 2)以完成各种α,β-不饱和醛(柠檬醛和取代的肉桂醛)的对映体互补环氧化。 ,提供了相应的α,β-环氧醛的两种对映体的通道。高转化率(高达98%),高对映选择性(高达98%ee)),并获得了良好的产品收率(50-80%)。反应可能通过反应性酶结合的亚胺离子中间体进行,从而通过蛋白质工程调节酶的活性和选择性。我们的结果强调了催化杂合在新的不依赖辅因子的氧化酶工程中的潜力。
A Highly Stereoselective Synthesis of Glycidic Amides Based on a New Class of Chiral Sulfonium Salts: Applications in Asymmetric Synthesis
A new type of chiral sulfoniumsalts that are characterized by a bicyclic system has been designed and synthesized from α‐amino acids. Their corresponding ylides, which were prepared by basic treatment of the sulfoniumsalts, reacted smoothly with a broad array of simple and chiral aldehydes to provide trans‐epoxy amides in reasonable to very good yields and excellent stereoselectivities (>98 %). The