A bidentate NHC-alkenyl ruthenium(II) complex via vinyl C-H bond activation

A bidentate NHC-alkenyl ruthenium(II) complex has been obtained on deprotonation of imidazolium salts with a N-CH2CH2X branch (X = OMe, Cl) followed by reaction with [RuCl2(P-cymene)](2). Low-temperature NMR studies and intermediate trapping with BH3 indicate the formation of a CH2 = CH-NHC carbene followed by the intramolecular activation of a vinyl Sp(2) C-H bond on coordination to a ruthenium(H) center.