Regioselective nucleophilic additions to tricarbonyl(η6-arene)chromium(0) complexes: electronic versus chelation control

Abstract

Regioselective addition of t-butyl-lithium to tricarbonyl(η⁶-benzyl alcohol)chromium(0) proceeds to give tricarbonyl(η⁶-5-methylene-6-exo-t-butylcyclohexa-1,3-diene)chromium(0), which can be isomerised to tricarbonyl(η⁶-o-t-butyltoluene)chromium(0). Repetition of the reaction on tricarbonyl(η⁶-1 -phenethanol)chromium(0) gives regio- and stereo-selectively the corresponding 5-ethylidene complex.