Brønsted acid-catalyzed reaction of alkynyltrifluoroborates with acetals and ketals

Abstract

The synthesis of small molecules is crucial in the pharmaceutical industry for producing drugs or biologically active compounds. Specifically, the formation of new carbon-carbon bonds is of great importance in synthetic organic chemistry. Brønsted acid catalysis is a powerful synthetic tool to make many different compounds, however, the current carbon-based nucleophiles are the major limitation of acid-catalyzed reactions. In effort to expand repertoire of Brønsted acid compatible nucleophiles, we present a novel carbon-carbon bond forming methodology between acetals, ketals, and potassium phenylacetylene trifluoroborate salts. Excellent functional group tolerance is observed with this protocol including, halogen, nitrile, nitro, acid and carbonyl functionalities.