Oxidative cyclopalladation triggers the hydroalkylation of alkynes  

作　　者：Kangbao Zhong Shihan Liu Xiaoqian He Hao Ni Wei Lai Wenting Gong Chunhui Shan Zhuang Zhao Yu Lan Ruopeng Bai 

机构地区：[1]School of Chemistry and Chemical Engineering,Chongqing Key Laboratory of Theoretical and Computational Chemistry,Chongqing University,Chongqing 400030,China [2]College of Chemistry,and Institute of Green Catalysis,Zhengzhou University,Zhengzhou 450001,China [3]College of Chemistry,Chongqing Normal University,Chongqing 401331,China

出　　处：《Chinese Chemical Letters》2023年第10期146-152,共7页中国化学快报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Nos.22003006,21822303,22103008,22271034);Project supported by graduate research and innovation foundation of Chongqing,China(No.CYB20045);a project(No.2018CDXZ0002)supported by the Fundamental Research Funds for the Central Universities(Chongqing University)。

摘　　要：This report describes the oxidative cyclopalladation activation of a C≡C bond during the Pd-catalyzed hydroalkylation of alkynes and analyzes potential reaction pathways based on density functional theory calculations. The more favorable pathway in-volves an oxidative cyclopalladation to generate a palladacyclopropene intermediate, which is rarely examined in Pd-catalyzed alkyne transformations. The reaction pathway proposed herein is kinetically favorable relative to the commonly proposed alkyne insertion mode. Furthermore, the Laplacians of the electron density, interaction region indicators, Mayer bond orders, and localized orbital bonding are evaluated to determine the reaction processes and characterize the key intermediates. Theoretical calculations indicate covalent bonding between a Pd(II) center and the two C-atoms in three-membered palladacycle species. Finally, electrostatic potential analysis reveals that the regioselectivity is governed by the charge distribution on the palladacycle moiety during the protonation step.

关 键 词：Pd catalysis Alkynes activation Hydrazones activation Oxidation state DFT 

分 类 号：O621.251[理学—有机化学]