One-pot Synthesis of Terminal Vinylphosphonates Catalyzed by Pyridine Grafted GO as Reusable Acid-Base Bifunctional Catalyst

Pyridine grafted graphene oxide (Py-GO) as an acid-base bifunctional catalyst was found to show cooperative catalysis in the one-pot synthesis of vinylphosphonates. In the presence of this catalyst, a variety of vinylphosphonates were synthesized by the reaction of different aldehydes (aryl, heteroaryl and alkyl aldehydes), phosphite esters and nitromethane in water. The present method is the first report for the one-pot synthesis of terminal vinylphosphonates using a reusable heterogeneous catalyst through a cascade Henry-Michael reaction followed by nitro elimination. This protocol offers several advantages such as using a simplified one-pot synthetic process with step saving, the least amount of waste, and low operational cost. Furthermore, the heterogeneous catalyst was successfully recovered and reused five times with unaltered catalytic activity.