艾伦
催化作用
化学
双金属片
位阻效应
钯
芳基
轴手性
烷基化
对映选择合成
反应性(心理学)
组合化学
立体化学
药物化学
有机化学
烷基
医学
病理
替代医学
作者
Ling Zhao,Yicong Luo,Junzhe Xiao,Xiaohong Huo,Shengming Ma,Wanbin Zhang
标识
DOI:10.1002/ange.202218146
摘要
Abstract The stereodivergent synthesis of allene compounds bearing α,β‐adjacent central chiralities has been realized via the Pd/Cu‐catalyzed dynamic kinetic asymmetric alkylation of racemic allenylic esters. The matched reactivity of bimetallic catalytic system enables the challenging reaction of racemic aryl‐substituted allenylic acetates with sterically crowded aldimine esters smoothly under mild reaction conditions. Various chiral non‐natural amino acids bearing a terminal allenyl group are easily synthesized in high yields and with excellent diastereo‐ and enantioselectivities (up to >20 : 1 dr, >99 % ee). Importantly, all four stereoisomers of the product can be readily accessed by switching the configurations of the two chiral metal catalysts. Furthermore, the easy interconversion between the uncommon η 3 ‐butadienyl palladium intermediate featuring a weak C=C/Pd coordination bond and a stable Csp 2 −Pd bond is beneficial for the dynamic kinetic asymmetric transformation process (DyKAT).
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