An alkylphosphonyl nucleophilic substitution reaction that proceeds by an elimination–addition mechanism with an alkylidineoxophosphorane (phosphene) intermediate

Abstract

For the phosphonamidic chloride R₂CHP(O)(NEt₂) Cl having R₂CH = 9-fluorenyl, substitution at phosphorus is unexpectedly fast with Et₂NH as the nucleophile, and discriminates less than is usual between competing Me₂NH and Et₂NH nucleophiles; such behaviour is consistent with an elimination-addition mechanism and a fluorenylidineoxophosphorane intermediate 8.