Improved Preparation of 1,3-Bis(2,6-di-iso-propylphenyl)imidazolium Tetrafluoroborate

Abstract

A convenient, high-yielding, multi-hundred-gram preparation of 1,3-bis(2,6-di-iso-propylphenyl)imidazolium tetrafluoroborate is described. The preparation of this salt has significant advantages over the chloride as it eliminates potential bis(chloromethyl) ether formation. The improved conditions provided the tetrafluoroborate salt in 61% overall yield in two steps from 2,6-di-iso-propylaniline.

GRAPHICAL ABSTRACT

Keywords:

• N-Heterocycle carbene
• IPr-HBF₄
• ligand preparation

ACKNOWLEDGMENT

I thank M. Okabe for valuable input during the preparation of the manuscript.