REACTIONS OF ARYLAZOSULFONES WITH THE CONJUGATE BASES OF ACTIVE-METHYLENE COMPOUNDS

The reaction between arylazo p-tolyl sulfones 1a-f (Ar-N=N-SO2-p-Tol) and the potassium salts of some active-methylene compounds (CH(2)XY: X , Y = CN, COOEt) represents an example of unprecedented behaviour of a zosulfones and effectively leads, depending on the nucleophile, to eit her unsymmetrical (6-8) or symmetrical (9) tetrasubstituted ethylenes. Of particular interest is the possibility to synthesize, in high yiel ds and mild conditions, polarysed ethylenes [ArNHCX=CXY: X = Y = CN (6 ) or X = COOEt, Y = CN (7)] some of which are otherwise not easily acc essible. A mechanism involving successive condensation processes is su pported by experimental evidence.