Synthesis of phosporus heterocycles using the donor-stabilized dithiomonometaphosphoryl chloride as preparative tool

The reactivity of the donor-stabilized monometaphosphoryl chloride Py doubl e right arrow PS2Cl (1) versus multiple bond systems and organometallic com pounds has been studied. Thus, on the reaction of 1 with diphenyl acetylene at elevated temperature the five-membered ring systems 24 are formed. In t he first step probably cycloaddition of the intermediary liberated free mon ometaphosphoryl chloride PS2Cl with diphenyl acetylene leads to the 1-thia- phosphacyclobut-3-ene 6. This assumption will be supported by theoretical c alculations. Attempts to eliminate one sulfur atom front the disulfide brid ge in 2 result in the bicyclic ring system 5 besides a compound which is as sumed to be 6. The reaction of 1with tertBuLi gives the dithiaphosphetane 7 whereas with NaN(SiMe3)(2) the diazadiphosphetidine 8 is obtained.