Benzylic Imidazolidinium, 3,4,5,6‐Tetrahydropyrimidinium and Benzimidazolium Salts: Applications in Ruthenium‐Catalyzed Allylic Substitution Reactions

Imidazolidinium, tetrahydropyrimidinium and benzimidazolium salts were prepared. Upon reaction with t BuOK, they generate carbene ligands, which were associated in situ to [RuCp*(MeCN) 3 ]PF 6 to produce ruthenium catalysts that are active for the substitution of allylic substrates by dimethyl malonate as a carbonucleophile and phenol. The influences of the N‐heterocyclic structures, as well as that of the benzylic N ‐substituents, on the reactivity and regioselectivity were examined.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)