Synthesis of ß,ß-Disubstituted Styrenes via Trimethylsilyl Trifluoromethanesulfonate-Promoted Aldehyde-Aldehyde Aldol Coupling-Elimination.

In the presence of trimethylsilyl trifluoromethanesulfonate (TMSOTf) and 2,6-lutidine, α,α-disubstituted aldehydes condense with electron-rich aromatic aldehydes to yield ß,ß-disubstituted styrenes. More electron-rich aromatic aldehydes react more rapidly and in higher yield. Preliminary results suggest that the reaction may proceed via the ionization and formal deformylation of an aldol intermediate.