Mechanistic Studies on a Cooperative NHC Organocatalysis/Palladium Catalysis System: Uncovering Significant Lessons for Mixed Chiral Pd(NHC)(PR3) Catalyst Design

被引：168

作者：

Guo, Chang ^{[1
]}

Janssen-Mueller, Daniel ^{[1
]}

Fleige, Mirco ^{[1
]}

Lerchen, Andreas ^{[1
]}

Daniliuc, Constantin G. ^{[1
]}

Glorius, Frank ^{[1
]}

机构：

[1] Westfal Wilhelms Univ Munster, Inst Organ Chem, Corrensstr 40, D-48149 Munster, Germany

来源：

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY | 2017年 / 139卷 / 12期

关键词：

N-HETEROCYCLIC CARBENE; TRANSITION-METAL CATALYSIS; MONODENTATE P-LIGANDS; DIELS-ALDER REACTION; ASYMMETRIC HYDROGENATION; OLEFIN HYDROGENATION; ENANTIOSELECTIVE HYDROGENATION; PHOTOREDOX CATALYSIS; GAMMA-BUTYROLACTONES; ALLYLIC ALKYLATION;

D O I：

10.1021/jacs.7b00462

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

A comprehensive investigation of the mechanism of the highly enantioselective Pd(PPh3)(4)/NHC-catalyzed annulation of vinyl benzoxazinanones and enals has been conducted. A study of reaction orders supports the postulated cooperative catalysis. Interestingly, a detailed investigation of the catalytically active palladium species pointed toward a dual role of the NHC acting as an organocatalyst and forming a novel mixed ligand Pd/NHC/phosphine complex. The catalytically active Pd/NHC/phosphine complex represents a new class of chiral palladium catalyst. Remarkably, phosphine plays a crucial role in this transformation. These complexes could be characterized by X-ray crystallographic analysis and employed as catalysts for the enantioselective [4 + 1] annulation reaction of vinyl benzoxazinones and sulfur ylides in good yields and good enantioselectivities.

引用

页码：4443 / 4451

页数：9