Synthesis of 1-Methyl-2-phenyl- and Bis(1-methyl-2-phenylethyl)phosphinic Acids from Red Phosphorus and Allylbenzene

摘要

Phosphinic acids are widely used as extragents of heavy metals, antipyrens, ligands for the design of metal complexes, building blocks in organic synthesis, and as biologically active compounds [1, 2]. At the same time, these acids still remain difficultly accessible compounds, since the methods of their synthesis are laborious, production-unfriendly, and based on toxic phosphorus halides [1]. Direct reactions of elemental phosphorus with electrophiles (organyl halides, acetylenes, or alkenes) in the presence of strong bases is an evident alternative to these methods for the formation of the C-P bond opening a practical route to the synthesis of the key organophosphorous compounds, including organophosphorous acids [3, 4]. For example, phosphorylation of vinylarenes (styrenes [5, 6], 2-vinylnaphthalene [7], vinylpyridines [8, 9]) with red phosphorus in the system KOH-DMSO presents an efficient method for the preparation of tertiary phosphine oxides and phosphinic acids (the latter, as a rule, are formed in a low yield).