Stereoselective synthesis of ambiphilic alkenes via regioselective methylation of α-trifluoromethanesulfonyl carbonyl compounds with trimethylsilyldiazomethane

α-Trifluoromethanesulfonyl esters, ketones and amides are C–H acids capable of reacting with trimethylsilyldiazomethane to afford the corresponding ambiphilic alkenes. While esters were found to be non-selective, ketones were highly regioselective for O-methylation and displayed variable E/Z stereoselectivity. Amides were observed to be both highly regio- and stereoselective, affording O-methylation with exclusive formation of the Z-alkene.