‘Reductive Heck reaction’ of 6-halopurines

Alkenylation of 9-benzyl-6-halopurines with alkenes does not proceed under conventional Heck conditions. However, in the presence of triethylammonium formate a mixture of the corresponding saturated products was obtained. In contrast to the classical Heck reaction, the regioselectivity of this process is low giving a mixture of both α- and β-products regardless of the electronic nature of the substituent on the double bond of the alkene.