A novel approach to 6-arylpurines based on [2+2+2]-co-cyclotrimerization of 6-alkynylpurines with various alpha,omega-diynes is described. Co-cyclotrimerization is catalyzed by Ni- and Co-phosphine catalysts and their choice depends on the substitution pattern of the both reactants. (C) 2003 Elsevier Science Ltd. All rights reserved.