The scope and limitations of deuteration mediated by Crabtree's catalyst

Exchange of protons for deuterons mediated by Crabtree's catalyst, 1, is di rected efficiently by a functional group containing an sp(2)-hybridised nit rogen or oxygen atom; more electron-rich substrates are, in general, deuter ated more efficiently. The electronic effects of substituents in the arene ring are critical only where the directing group is poor, in which case exc hange is generally promoted by electron donating substituents, but the exch ange is impeded by bulky meta-substituents. (C) 2001 Elsevier Science Ltd. All rights reserved.