Pyrazole–pyridine–pyrazole (NNN) ruthenium(<scp>ii</scp>) complex catalyzed acceptorless dehydrogenation of alcohols to aldehydes
Yinyin Chen, Tianhua Cui, Hua Chen, Xueli Zheng, Haiyan Fu, Ruixiang Li
Abstract
), were synthesized and characterized with NMR, HRMS, and single-crystal X-ray diffraction. Their catalytic application was investigated in the acceptorless dehydrogenation (AD) of primary alcohols. Complex 1 outperformed 2 and 3 in terms of the selectivity towards the aldehydes, and provided the aldehydes with a yield of up to 99%, with good functional group tolerance under mild conditions. In addition, the only by-product of the reaction was dihydrogen, which can be collected as clean energy, and the reaction meets the requirements of environment-friendly chemistry. Complex 1 also proved to be a promising catalyst in the sequential AD/condensation reaction between the primary and secondary alcohols, affording α,β-unsaturated ketones in moderate to good selectivity.