Arene Ru (II)‐catalyzed facile synthesis of N‐acylhydrazones via acceptorless dehydrogenative coupling strategy

Abstract

A facile catalytic one‐pot synthesis of N‐acylhydrazones via acceptorless dehydrogenative coupling of readily available alcohols and benzohydrazides (R2CONHNH2) using arene ruthenium (II) complexes has been described. The coupling of alcohols with various benzohydrazides using ruthenium catalysts provide a wide range of N‐acylhydrazones in good to excellent yields (63–93%; 32 examples). The present protocol offers high selectivity of hydrazones without any alkylated products and tolerates a range of functional groups. Control experiments indicate that the mechanism proceeds via acceptorless dehydrogenation of alcohols, and hydrogen and water are the sole by‐products. The gram scale synthesis illustrates the usefulness of the present strategy.

Integrating MOF‐Based Catalysis with Nanocavity‐Confined Pd Catalysis over Multifunctional Pd‐MOF‐Fe for Acceptorless Dehydrogenation of Alcohols under Visible Light

“…[7][8][9][10] More importantly, the value-added carbonyl compounds can be synchronously formed during the ADAs process, thus improving the atomic efficiency. [11] Nowadays, ADAs employing homogeneous Ru, [12,13] Ir, [14][15][16] Au, [17,18] and Pt [19] catalysts have been reported as effective catalysts. [20,21] However, these developed systems encounter the drawbacks of difficulties in catalyst recyclability and requirement of acid or base additives.…”