Mn-Catalyzed Three-Component Reactions of Imines/Nitriles, Grignard Reagents, and Tetrahydrofuran: An Expedient Access to 1,5-Amino/Keto Alcohols

An expedient Mn-catalyzed three-component synthesis of 1,5-amino/keto alcohols from Grignard reagents, imines/nitriles, and tetrahydrofuran (THF) is described, which deviates from the classic Grignard addition to imines/nitriles in THF solvent. THF is split and “sewn” in an unprecedented manner in the reaction, leading to the formation of two geminal C–C bonds via C–H and C–O cleavage. Mechanistic experiments and DFT calculations reveal radical and organo-Mn intermediates in the catalytic cycle and the α-arylative ring-opening of THF as the key reaction step.