The Chemistry of Cyclic Carbaphosphazenes: The First Observation of (R₂PN)(ClCN)₂ (R═Cl, Ph) as a Reagent for the Conversion of Alcohols to Aldehydes, Ketones, and Alkyl Chlorides

Abstract

The oxidation of nine primary and secondary alcohols to the corresponding aldehydes and ketones has been carried out under mild conditions and in good yields using the cyclocarbaphosphazenes (R₂ PN)(ClCN)₂ [R₂P = Cl₂P( 1 ), Ph₂P( 2 )] along with dimethylsulfoxide. While both the P═Cl and C─Cl bonds of the carbaphosphazene can in principle bring about the reaction, we observed an increased preference for the C═Cl bonds over the P═Cl bonds in the oxidation of alcohol. Blocking the reactive P site on the heterocyclic ring with the phenyl groups was found to reduce the yields of the oxidized products, while blocking the C- sites with diethylamino groups resulted in no reaction. In addition, along with DMF, the same cyclocarbaphosphazene has been found to be useful for the conversion of alcohols to alkyl chlorides.

Keywords:

• Aldehydes
• alkyl chlorides
• cyclocarbaphosphazene
• dimethylformamide
• dimethyl sulfoxide
• oxidation

Acknowledgments

We thank Department of Science and Technology, India, for financial assistance in the form of a research grant to Anil J. Elias.