Tuning the Catalyst Reactivity of Imidazolylidene Catalysts through Substituent Effects on the N-Aryl Groups

Ryuji Kyan; Kohei Sato; Nobuyuki Mase; Naoharu Watanabe; Tetsuo Narumi

doi:10.1021/acs.orglett.7b01105

Tuning the Catalyst Reactivity of Imidazolylidene Catalysts through Substituent Effects on the N-Aryl Groups

Org Lett. 2017 May 19;19(10):2750-2753. doi: 10.1021/acs.orglett.7b01105. Epub 2017 May 9.

Authors

Ryuji Kyan¹, Kohei Sato¹, Nobuyuki Mase¹, Naoharu Watanabe¹, Tetsuo Narumi¹

Affiliation

¹ Department of Engineering, Graduate School of Integrated Science and Technology, ‡Research Institute of Green Science and Technology, and §Graduate School of Science and Technology, Shizuoka University , 3-5-1 Johoku, Hamamatsu, 432-8561 Shizuoka, Japan.

PMID: 28485951
DOI: 10.1021/acs.orglett.7b01105

Abstract

A series of imidazolium salts with various N-aryl groups were synthesized, and their catalytic activities were evaluated to investigate the contribution of the N-aryl groups to the catalytic activity in the synthesis of γ-butyrolactone through an a³→d³-umpolung addition. Imidazolylidenes with 2,6-diethylphenyl groups were effective catalysts, and several mechanistic studies, including a deuterium kinetic isotope effect study, revealed that both steric and kinetic effects were responsible for the enhanced catalytic activity.

Publication types

Research Support, Non-U.S. Gov't