Reaction of Phenylenedioxytrihalogenophosphoranes with Arylacetylenes. Synthesis and Spatial Structure of the Derivatives of 2-Oxo-4-Aryl-5,6-Benzo-1,2-Oxaphosphorin-2-Enes

New method of synthesis of six-membered heterocycles – 2-R-2-oxo-4-aryl-2H-benzo[e][1,2]-oxaphosphorin-3-enes has been developed. It includes the interaction of arylenedioxy trihalogenophosphoranes with arylacetylenes. The formation of phosphoryl group and P-C bond, ipso-substitution of the aromatic oxygen and halogenation of the benzene ring take place in this unusual reaction. The influence of the phosphorane structure on synthetic result is discussed. If both para positions at benzene ring of the phosphorane are occupated by halogens, the evolving of halogen molecule occurs. The structures of 2-R-2-oxo-4-aryl-2H-benzo[e][1,2]-oxaphosphorin-3-enes are determined by X-ray analysis.