Improved synthesis of N-heterocyclic olefins and evaluation of their donor strengths

An improved synthesis of N-heterocyclic olefins (NHOs) containing terminal CH2 donor groups was developed. A preliminary investigation of the bonding mode and donor strengths of various structurally distinct NHOs was conducted by analysis of the IR and NMR spectra of their corresponding rhodium carbonyl complexes NHO center dot RhCl(CO)(2), along with examination of pertinent metrical parameters via X-ray crystallography and Density Functional Theory (DFT) computations. (C) 2015 Elsevier Ltd. All rights reserved.