4-Dimethylaminopyridine borane, DMAP-BH3
The lewis base-borane complex 4-dimethylaminopyridine borane is a potent hydrogen atom donor in radical reductions.
4-Dimethylaminopyridine-BH3 as the boryl radical precursor promotes a desulfurizative reduction to access organic amines in the presence of PhSH as the polarity reversal catalyst. Alternatively a N-heterocyclic carbene-BH3 as the boryl radical precursor and sterically bulky Ph3CSH as catalyst can be used for annulation of unsaturated thioamides allowing for the construction of N-heterocyclic and carbocyclic skeletons.
Y.-J. Yu, F.-L. Zhang, J. Cheng, J.-H. Hei, W.-T. Deng, Y.-F. Wang, Org. Lett., 2018, 20, 24-27.