Recent Developments in Dehydrogenative Organic Transformations Catalyzed by Homogeneous Phosphine‐Free Earth‐Abundant Metal Complexes

Abstract

Stoichiometric amounts of various oxidants have long been employed for the oxidation of organic compounds. The major drawback of this method is the amount of toxic waste produced, which is in sharp contrast to principles of green chemistry. In catalytic dehydrogenation pathways, hydrogen carrier organic compounds (HCOCs) containing O−H, C−H, and N−H bonds can be transformed to their oxidized forms by removing two hydrogen atoms from the starting materials. Among the homogeneous transition metal‐ligand complexes that have been applied in a catalytic dehydrogenative approach, phosphine ligands have frequently been used. Over the past decades, phosphine‐free ligand systems have since been developed and implemented in various organic reactions to overcome the drawbacks associated with phosphine‐based catalysts. The aim of this review is to summarize the use of non‐phosphinic ligand‐metal complexes in organic transformations proceeding by a dehydrogenative pathway.

Recent advances in C/N-alkylation with alcohols through hydride transfer strategies

“…4 Established pioneers of hydrogen shuttle catalysis have covered these methodologies to some extent in previous reviews focusing on relevant subtopics such as synthesizing heterocycles 5,6 and designing ligands. 7,8 Additionally, previous reviews have been published introducing the background and perspective of each individual metal separately: Co by Kundu 9 and Young, 10 Mn (Mukherjee), 11 Ru and Ir (Rit), 12 and Fe (Anilkumar), 13 to name but a few.…”