Sustainable Aerobic Allylic C–H Bond Oxidation with Heterogeneous Iron Catalyst

Abstract

Emerging techniques are revolutionizing the realm of chemical synthesis by introducing new avenues for C−H bond functionalization, which have been exploited for the synthesis of pharmaceuticals, natural compounds, and functional materials. Allylic C−H bond oxidation of alkenes serves as possibly the most employed C−H bond functionalization reaction. However, sustainable and selective approaches remain scarce, and the majority of the existing conditions still hinge on hazardous oxidants or costly metal catalysts. In this context, we introduce a heterogeneous iron catalyst that addresses the above-mentioned concerns by showcasing the aerobic oxidation of steroids, terpenes, and simple olefins to the corresponding enone products. This novel method provides a powerful tool for the arsenal of allylic C−H bond oxidation while minimizing the environmental concerns.

Cobalt-Catalyzed Acceptorless Dehydrogenation of Primary Amines to Nitriles

“…Although alcohol acceptorless dehydrogenation has been realized with non-noble metal catalysts such as Fe, Co, , and Mn, , all previous reports of primary amine dehydrogenation required noble metals, as illustrated above (Ir, Rh, Ru). In line with our interests in metal–ligand cooperative dehydrogenation and non-noble metal catalysis, we desired to develop a non-noble metal system for oxidant- and hydrogen acceptor-free amine dehydrogenation. Inspired by a pyridinylpyrazole ligand first reported by Satake and use of the corresponding η 3 -allylpalladium- N , N complex for cyclopropanation, we designed a novel cationic [Cp*Co­( t BuPPH)­I] + I – complex and explored its catalytic ability in alcohol dehydrogenation and dehydrogenative coupling reactions .…”