Expedient tandem dehydrogenative alkylation and cyclization reactions under Mn(i)-catalysis

Sustainable chemical production requires fundamentally new types of catalysts and catalytic technologies. The development of coherent and robust catalytic systems based on earth-abundant transition metals is essential; however, it is extremely challenging. Herein, an expedient divergence strategy for tandem dehydrogenative alkylation and cyclization reactions of hydrazides is reported under manganese catalysis. Using abundantly available alcohols (including MeOH, EtOH) and earth-abundant metal catalysts with water as a sole by-product makes the present strategy more sustainable and affordable. Interestingly, unsymmetrical selective deuterium incorporation is also presented for the first time. Several selective bond activation/formation reactions occur sequentially via amine-amide metal-ligand cooperation.