Stereoconvergent Access to Z‐Allylborons from E/Z‐Mixed 1,3‐Dienes via Cu‐Guanidine Catalysis

• DOI: 10.1002/adsc.202401322
• Publication Date: 2024-11-12T03:36:06Z
• Authors: Ai Zhang; Huangfeng Zhang; Tao Jin; Lin Ge; Xiaoyan Ma; Jinghua Tang; Jinyu Liu; Choon‐Hong Tan; Richmond Lee; Yicen Ge
• Keywords: Guanidine

Merging the stereoisomeric mixture of substrate into a single product through stereospecific transformation is challenging but higher‐order synthetic strategy, which perfectly meets demand cost control in precise chemical production. In this work, stereoconvergent synthesis Z‐allylic boronates was realized with protoborylation E/Z‐mixed 1,3‐dienes catalyzed by novel copper‐guanidine complex. The reaction could proceed smoothly under very mild conditions good functional group tolerance, and convert diverse aryl‐substituted desired Z‐1,4‐addition products excellent chemo‐, regio‐, stereoselectivities minutes. Detailed mechanistic studies also helped to disclose origin stereoconvergency. Both E‐ Z‐diene were found directly undergoing rapid borylation without E/Z isomerization C=C bond, followed convergent formation same thermodynamically stable allylcopper intermediate before slow protonation step occurred.