NiH-Catalyzed Regioselective Reductive Arylation of Remote and Proximal Olefins

Author:He Yu Li

Supervisor:zhu shao lin

Database:Doctor

Degree Year:2019

Download:36

Pages:126

Size:6019K

Keyword:

The remote sp3 C-H functionalization based on nickel hydride chemistry in our group is an important research area due to its unique advantages such as mild reaction conditions,good selectivity,and wide substrate range.In the first chart of this thesis,we summarized the recent progress on the transition metal-catalyzed remote C-H functionalization,various reaction mechanisms of remote functionalization of alkenes based on metal-hydride,and different types of functionalization.Based on these previous results,we realized a mild and regioselective NiH-catalyzed arylation of remote and proximal olefins.This activation model also plays a good complement to the current sp3 C-H activation strategies.Our research is divided into two parts:In the first part,by synergistic combination of NiH-catalyzed alkene isomerization and nickel-catalyzed cross-coupling,a general protocol for the remote hydroarylation was achieved from readily accessible olefin starting materials.A wide range of structurally diverse 1,1-diarylalkane could be obtained in high yields and excellent regioselectivities.The practicality and synthetic flexibility of this approach is highlighted by the successful employment of isomeric mixtures of olefins for regioconvergent arylation.In the second part,through NiH-catalyzed alkene isomerization-hydroarylation process,we realized a remote hydroarylation reaction with terminal-selective from unactivated internal olefins.We demonstrated that the excellent terminal-selective could be achieved by using an easy prepared pyrox ligand under mild reaction conditions.The practicality and synthetic flexibility of this approach is highlighted by the successful employment of petroleum-derived isomeric mixtures of olefins to value-added linear arylation products on gram-scale in a regioconvergent way.