Enantioselective Addition of Activated Terminal Alkynes to 1-Acylpyridinium Salts Catalyzed by Cu-Bis(oxazoline) Complexes

摘要

We have developed the first catalytic asymmetric addition of 1-alkynes to 1-acylpyridinium salts. It was found that the carbonyl group in the 3 position of the 1-alkynes is important for the enantioselectivity of the reaction. These findings may shed light on other additions using 1-alkynes as substrates. The reaction provides highly functionalized dihydropyridines with excellent enantioselectivity, which are valuable building blocks for assembling complex N-heterocycles. Further exploration of the scope and limits of the synthetic application is in progress.