Highly efficient Markovnikov hydroaminocarbonylation of alkenes and alkynes catalyzed by a “soluble” heterogeneous Pd catalyst

Abstract

Highly efficient and regioselective synthesis of amides from simple starting materials remains a great challenge. Herein, we reported a highly efficient hydroaminocarbonylation of alkenes and alkynes with amines and CO gas catalyzed by a soluble heterogeneous Pd catalyst (Pd@PPOC), in which ultrafine Pd nanoparticles (NPs) were homogeneously dispersed in a well-defined and discrete triphenyl phosphine-built-in porous organic cage (PPOC). The catalyst Pd@PPOC exhibited superior catalytic activity and excellent regioselectivity to Markovnikov adducts, outperforming those previous state-of-the-art Pd catalysts. A diverse set of branched amides and α,β-unsaturated amides were synthesized in high yields, and with broad substrate scopes spanning a range of functional groups that were well tolerated in this synthetic protocol. Remarkably, the soluble catalyst Pd@PPOC demonstrated high stability and could be easily separated and reused up to 10 times with maintenance of the catalytic performance and original structural nature. This study not only provides an efficient and sustainable synthetic method for accessing amides, but also highlights the potential of the MNPs encapsulated in the functional POCs for regioselective catalysis.