Acceptorless Dehydrogenative Cyclization of N-Tosylhydrazones and Anilines: Dual Role of Tris(pentafluorophenyl)borane
Debasis Koley and Biplab Maji show the dual role of tris(pentafluorophenyl)borane in cyclization reactions
Tris(pentafluorophenyl)borane [B(C6F5)3] acts as a powerful Lewis acid catalyst for numerous organic transformations. In combination with a sterically demanding Lewis base, it forms Frustrated Lewis acid Pairs (FLPs), which have recently been applied for small-molecule activations and metal-free hydrogenation as well as dehydrogenation reactions. Recently, the group of Professor Debasis Koley and Professor Biplab Maji at the Indian Institute of Science Education and Research (Kolkata, India) described the B(C6F5)3-catalyzed cyclization of N-tosylhydrazones and anilines to form triaryl-1,2,4-triazoles, which are essential heterocyclic scaffolds in pharmaceutical, biological, and materials sciences.