Homologation of n-alkanes on tungsten films. A novel, highly selective reaction of intermediate carbenes

Abstract

The n-alkanes (C₅) undergo a novel remarkably selective reaction in high yield whereby they are singly and multiply homologated to the higher n-paraffins during hydrogenolysis on tungsten films; the reaction, which also occurs on several other metal catalysts but there affords aromatic products at the higher temperatures employed, is discussed in terms of intermediate α-olefins and surface methylenes adding to each other in a highly selective fashion giving metallocyclobutanes, which in turn are hydrogenated to the homologous paraffin, or isomerize to new α-olefins with repetitive chain growth.