Microwave‐Promoted Efficient Synthesis of 2‐Phosphabicyclo[2.2.2]octadiene‐ and Octene‐2‐oxides under Solvent‐Free Conditions in Diels–Alder Reaction

Abstract

The microwave‐induced and solvent‐free Diels–Alder reaction of 1,2‐dihydrophosphinine oxides (1 and 5) and dimethyl acetylenedicarboxylate or N‐phenylmaleimide afforded 2‐phosphabicyclo[2.2.2]octadiene‐ (2 and 6) and phosphabicyclo[2.2.2]octene oxides (4 and 7), respectively, almost quantitatively and in a fast reaction in an ecofriendly manner.

Keywords:

• bridged P‐heterocycles
• Diels–Alder reactions
• 1,2‐dihydrophosphinine oxides
• green chemistry
• microwave synthesis
• solvent‐free conditions

Acknowledgments

This project was supported by joint funds from the European Union and the Hungarian State (GVOP‐3.2.2.‐2004‐07‐0006/3.0), as well as by the Hungarian Scientific and Research Fund (OTKA T 067679).