Selective alkylation of β-ketoester enolates using O-methyl aminosulfoxonium salts; the first example of C-alkylation using sulfoxonium salt electrophiles

Abstract

The alkylation of β-ketoester enolates with O-methyl aminosulfoxonium tetraphenylborate salts is reported; good to excellent selectivity for C-vs. O-alkylation is observed, and is found to be dependent on the nature of the β-ketoester, solvent, metal counterion and aminosulfoxonium salt.