DOUBLE ARBUZOV REACTION OF IN-SITU GENERATED BIS(TRIMETHYLSILOXY)PHOSPHINE WITH DIELECTROPHILES - METHODOLOGY FOR THE SYNTHESIS OF CYCLIC PHOSPHINIC ACIDS

Phosphetanic, phospholanic, phosphorinanic, phosphepanic, and phosphocanic acid derivatives have been prepared in a single step by the double Arbuzov reaction of bis(trimethylsiloxy)phosphine (BTSP) with dielectrophiles. Mild, thermal reaction conditions are employed during reaction of BTSP with 1,n-dihaloalkanes (n = 3-7), a ditriflate, and omega-bromo 1,2-epoxides possessing varying levels of steric congestion and functionalization. Isolation and manipulation of pyrophoric BTSP is avoided with in situ generation of the reagent from ammonium hypophosphite and hexamethyldisilazane. Monocyclic, bicyclic, and spirocyclic phosphinic acids are obtained after purification in moderate to good isolated yields. The developed methodology is of particular interest for synthesis of nonhydrolyzable analogues of cyclic phosphodiesters.