A Study on the Reduction of 4-Chloro-1,2-Dihydrophosphinine Oxides by Transfer Hydrogenation

Abstract

Under the conditions of transfer hydrogenation by ammonium formate, the title compounds (6) were converted to a mixture of the corresponding 1,2,3,6-tetrahyidrophosphinine oxide (7), its dechlorinated derivative (8) and the respective 1,2,3,4,5,6-hexahydrophosphinine oxide (9). In the phenyl-substituted instance, the ratios of the components depended on the mode of heating (traditional heating or microwave irradiation), temperature, and the solvent (toluene or [bmim][BF₄]) used. In the ethoxy-substituted series, the dechlorinated 1,2-dihydrophosphinine oxide (10b) was detected as an intermediate.

GRAPHICAL ABSTRACT

Keywords:

• Transfer hydrogenation
• 1,2-dihydrophosphinine oxide
• 1,2,3,6-tetrahydrophosphinine oxide
• 1,2,3,4,5,6-hexahydrophosphinine oxide
• dechlorination
• intermediate

Acknowledgments

The authors are grateful for the OTKA (K83118) support of this work. This work is connected to the scientific program of the “Development of quality-oriented and harmonized R+D+I strategy and functional model at BME” project. This project is supported by the New Széchenyi Plan (Project ID: TÁMOP-4.2.1/B-09/1/KMR-2010-0002).