Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, Frontiers Science Center for Transformative Molecules, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.
State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, 345 Lingling Lu, Shanghai, 200032, China.
Angew Chem Int Ed Engl. 2023 Feb 20;62(9):e202218146. doi: 10.1002/anie.202218146. Epub 2023 Jan 24.
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 -butadienyl palladium intermediate featuring a weak C=C/Pd coordination bond and a stable Csp -Pd bond is beneficial for the dynamic kinetic asymmetric transformation process (DyKAT).
通过 Pd/Cu 催化的外消旋烯丙基酯的动态动力学不对称烷基化反应,实现了具有 α,β-相邻中心手性的烯丙基化合物的立体发散合成。双金属催化体系的匹配反应活性使得具有空间位阻的芳基取代烯丙基乙酸酯与空间位阻较大的亚胺酯在温和的反应条件下能够顺利进行反应。各种末端烯丙基取代的手性非天然氨基酸很容易以高产率和优异的非对映选择性和对映选择性(高达>20:1 dr,>99%ee)合成。重要的是,通过切换两个手性金属催化剂的构型,可以很容易地获得产物的全部四个立体异构体。此外,具有弱 C=C/Pd 配位键和稳定的 Csp-Pd 键的不常见的η-丁二烯基钯中间体的易互变有利于动态动力学不对称转化过程(DyKAT)。