Triton-X-100 as an Organic Catalyst for One-Pot Synthesis of Arylmethyl-<i>H</i>-phosphinic Acids from Red Phosphorus and Arylmethyl Halides in the KOH/H₂O/Toluene Multiphase Superbase System

Abstract

Triton-X-100, a polyethylene glycol 4-(tert-octyl)phenyl ether, has been found to be an active micellar organic catalyst for the one-pot selective synthesis of arylmethyl-H-phosphinic acids in up to 65% yields by the direct phosphinylation of arylmethyl halides with red phosphorus in the KOH/H2O/toluene multiphase superbase system. The catalyst demonstrates a good recyclability. As a result, an expeditious method for the chemoselective synthesis of arylmethyl-H-phosphinic acids—versatile sought-after organophosphorus compounds—has been developed. The synthesis is implemented via direct alkylation/oxidation of red phosphorus with arylmethyl halides, promoted by superbase hydroxide anions using Triton-X-100 (a commercial off-the-shelf organic recyclable micellar catalyst). The reaction comprises the hydroxide anions-assisted disassembly of Pred 3D polymer molecules triggered by the separation from the potassium cation in ordinary crown-like micelles to produce polyphosphide anions in aqueous phase. Further, polyphosphide anions are alkylated with arylmethyl halides in organic phase in the presence of the catalytic Triton-X-100 reverse micelles and alkylated polyphosphide species undergo the double hydroxylation. The advantages of the strategy developed include chemoselectivity, benign and accessible starting reagents, catalyst recyclability, and facile one-pot implementation.

Keywords

• micellar catalysis
• red phosphorus
• Triton-X-100
• arylmethyl-<i>H</i>-phosphinic acids
• superbase
• phosphinylation