Combining Both Acceptorless Dehydrogenation and Borrowing Hydrogen Mechanisms in One System as Described by DFT Calculations

The mechanisms for the formation of N-substituted hydrazones by coupling of alcohols and hydrazine, achieved by the sequential processes of acceptorless dehydrogenation and borrowing hydrogen, has been unveiled by density functional theory (DFT) calculations. The release of water and molecular hydrogen as subproducts, combined with the Mn-PNN pincer based catalyst describe a green environment. Mechanistically, apart from describing a complex system of three coupled catalytic pathways, calculations describe the pivotal role of two intermediates, which participate in two catalytic pathways each one. Finally, predictive catalysis plays the role to push forward this reaction toward milder conditions, and thus in line with green chemistry standards A.P. is a Serra Húnter Fellow and ICREA Academia Prize 2019. S.S. and A.P. thank the Spanish MINECO for projects and PID2020-113711GB-I00 and PGC2018-097722-B-I0 Open Access funding provided thanks to the CRUE-CSIC agreement with Wiley