Reactions of the carbanions of substituted 2-cyanopropionamides and 2-cyanothiopropionamides: O- and S-methylation with methyl trifluoromethanesulfonate

alpha-Carbanions of the substituted 2-cyanopropionamides 5 (X = 0) and 2-cy anothiopropionamides 5 (X = S) react with trifluoromethanesulfonic acid to give the C-protonated systems 11, while methylation with methyl trifluorome thanesulfonate results in O- or S-methylation to give 12 (X = O or S). The X-ray crystal structure of 12c, an example of O-methylation, is presented. (C) 1999 John Wiley & Sons, Inc.