Mutualism in organic synthetic chemistry: Simultaneous heterodehydrocoupling of hydrostannane and reduction of quinoline

Abstract

Here we report a one-pot strategy to simultaneously achieve both the heterodehydrocoupling of hydrostannane and reduction of quinoline by using B(C6F5)3 as catalyst under mild conditions. This method realizes the synthesis of heteroatom-tin complexes (NSn/OSn/PSn/SSn) by the same catalyst system. With the assistance of quinoline, the substrate scope was broadened and ESn yield was significantly enhanced. During the reaction, the generated heterodehydrocoupling intermediate [ESnH]+[HB(C6F5)3]− would accelerate the quinoline reduction by transforming 1,4-N-stannyl-dihydroquinoline intermediate into N-stannyl-tetrahydroquinoline whereas 1,4-N-stannyl-dihydroquinoline could serve as hydrogen acceptor to facilitate the conversion of [ESnH]+[HB(C6F5)3]− intermediate to produce ESn (E = N/O/P/S). The metathetical reaction of N-stannyl-tetrahydroquinoline and EH rapidly generates ESn and tetrahydroquinolines, thus mutually promoting the above process. The reaction mechanism is proposed on the basis of control experiments, capture and synthesis of key intermediates and deuterium experiments.