Reaction of 2,2,2-trichlorobenzo[d]-1,3,2-dioxaphosphole-5-carbonylchloride with phenylacetylene: predominant formation of 2-(2-chloro-2-phenylethenyl)-2,2-dichlorobenzo[d]-1,3,2-dioxaphosphole-5-carbonylchloride

Abstract

The reaction of 2,2,2 trichlorobenzo[d] 1,3,2 dioxaphosphole 5 carbonylchloride with phenylacetylene in benzene (80 °C) afforded 2 (2 chloro 2 phenylethenyl) 2,2 dichloro benzo[d] 1,3,2 dioxaphosphole 5 carbonylchloride (yield >95%) as a result of the electro philic cis addition of the phosphorus(V) derivative at the triple bond of acetylene with retention of coordination of the P atom. Hydrolysis of this compound affords predominantly 2 hydroxy 5 (hydroxycarbonyl)phenyl (2 chloro 2 phenylethenyl)phosphonate.