A highly efficient dual catalysis approach for C-glycosylation: addition of (o-azaaryl)carboxaldehyde to glycals

A novel and efficient dual catalysis approach by concurrent activation of glycals and (o-azaaryl)-carboxaldehydes using palladium and N-heterocyclic carbene has been developed. The two electrophiles could react after activation through formation of the Breslow intermediate and a pi-allyl Pd complex, widening the scope of reacting glycosylation partners and opening up possibilities for future glycosylation.