Synthesis 2019; 51(10): 2058-2080
DOI: 10.1055/s-0037-1611751
review
© Georg Thieme Verlag Stuttgart · New York

Electronic Effects on Chiral NHC–Transition-Metal Catalysis

Xuefeng Yong ‡
b   School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, P. R. of China
a   Shenzhen Grubbs Institute, Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, P. R. of China   Email: jasonhcy@sustech.edu.cn
,
Ryan Thurston ‡
c   Department of Chemistry & Pharmacy, Friedrich Alexander University Erlangen-Nürnberg, Nikolaus-Fiebiger-Str. 10, 91058 Erlangen, Germany
a   Shenzhen Grubbs Institute, Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, P. R. of China   Email: jasonhcy@sustech.edu.cn
,
Chun-Yu Ho*
a   Shenzhen Grubbs Institute, Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, P. R. of China   Email: jasonhcy@sustech.edu.cn
› Author Affiliations
We thank Shenzhen Nobel Prize Scientists Laboratory Project (C17213101), NSFC (21602099), SZ basic research fund (JCYJ 20170817105041557) and Shenzhen Key Laboratory of Full Spectral Solar Electricity Generation (FSSEG) (ZDSYS201602261933302).
Further Information

Publication History

Received: 20 December 2018

Accepted after revision: 30 January 2019

Publication Date:
10 April 2019 (online)


These authors contributed equally to this work.

Abstract

Though the properties of N-heterocyclic carbenes (NHCs) are generally dominated by the very strong σ donating character, electronic activation has emerged as an effective method to cooperate with typical carbon-framework steric optimization for highly enantioselective chiral NHC–transition-metal catalysis in recent years. NHC electronic changes associated with structural variations are now better understood by quantitative analysis using various methods. Here we highlighted and correlated some interesting chiral induction improvement methods, which were brought by electronic and steric cooperation on chiral NHC–transition-metal catalysis.

1 Introduction

2 Hemilabile Sidechains on NHC Ligands

3 Electronic and Bond Angle Changes Brought by NHC Core Size Variations

4 Electronic Activators on the NHC Core

5 Conjugated Systems and Fused Ring Structures

6 Remote Electronic Activators on the N-Aryl Ring

7 Summary and Outlook