Cycloelimination of imidazolidin-2-ylidene N-heterocyclic carbenes: mechanism and insights into the synthesis of stable "NHC-CDI" amidinates

Aleksandr V Zhukhovitskiy; Julie Geng; Jeremiah A Johnson

doi:10.1002/chem.201500052

Cycloelimination of imidazolidin-2-ylidene N-heterocyclic carbenes: mechanism and insights into the synthesis of stable "NHC-CDI" amidinates

Chemistry. 2015 Apr 7;21(15):5685-8. doi: 10.1002/chem.201500052. Epub 2015 Feb 20.

Authors

Aleksandr V Zhukhovitskiy¹, Julie Geng, Jeremiah A Johnson

Affiliation

¹ Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (USA).

PMID: 25704668
DOI: 10.1002/chem.201500052

Abstract

We report the discovery that 1,3-bis(aryl)imidazolidin-2-ylidenes, one of the most widely studied classes of N-heterocyclic carbenes (NHCs), undergo quantitative conversion to zwitterionic "NHC-CDI" amidinates upon heating to ≈100 °C in solution. The mechanism of this novel NHC decomposition process is studied in detail. These studies enabled the rational synthesis of a new class of bench stable amidinates from a panel of NHCs and carbodiimides. We expect these constructs to find utility in a variety of applications.

Keywords: amidinate; carbene; carbodiimide; cycloelimination; decomposition; pericyclic reaction.

Publication types

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

MeSH terms

Amidines / chemical synthesis*
Amidines / chemistry
Crystallography, X-Ray
Imidazoles / chemical synthesis
Imidazoles / chemistry*
Methane / analogs & derivatives*
Methane / chemical synthesis
Methane / chemistry
Models, Molecular

Substances

Amidines
Imidazoles
carbene
Methane