The addition of amines to vinyl sulphones and sulphonamides

Abstract

The uncatalysed addition of primary and secondary amines to vinyl sulphones and sulphonamides in polar aprotic solvents has been shown to be of the first order with respect to vinyl groups and of the second order with respect to amine. The reactions are retarded by the addition of a tertiary amine. A mechanism is suggested in which the initial step is the addition of the amine itself to the double bond to form a solvent-stabilised dipolar intermediate which then reacts with a second molecule of amine. The addition of secondary amines is much slower than that of primary, probably for steric reasons.