Flexible Borane–Nitrogen Frustrated Lewis Pair Organic Microsphere for Selective Alkyne Hydrogenation

Abstract

Frustrated Lewis pairs (FLPs) have been increasingly utilized as metal-free catalysts for manufacturing pharmaceutical and agricultural products with strict control of metal residues. However, the moisture sensitivity and homogeneity of typical FLPs significantly inhibit their practical applications and, meanwhile, stimulate the development of heterogeneous catalysts capable of addressing these issues. In this work, we report a flexible approach to fabricate borane–nitrogen containing phenolic organic microspheres (BNPs), severing as a new, moisture-tolerant, and bench-stable heterogeneous FLP catalyst for molecular hydrogen activation for selective hydrogenation of structurally diverse terminal alkynes to the respective alkenes. Mechanistic studies further revealed a heterolytic hydrogen splitting process, in which the in situ formation of active hydroborane species was involved. Given the wild applicability of FLP, our protocol, thus, paves a way for advancing BNPs as a new member of the heterogeneous FLP family for catalysis.

Design and Synthesis of Heterogeneous Frustrated Lewis Pairs for Hydrogenation: From Molecular Immobilization to Defects Engineering

“…[90] Lu and coworkers proposed a flexible approach to fabricate borane-nitrogen containing phenolic organic microspheres (BNPs), serving as a new, moisture-tolerant, and bench-stable heterogeneous FLP catalyst for selective hydrogenation of structurally diverse terminal alkynes to the respective alkenes (Figure 4d). [91]…”