New Motifs in Deoxydehydration: Beyond the Realms of Rhenium

Abstract

The deoxydehydration (DODH) reaction remains one of the most efficient methods of reducing the oxygen content of biomass while keeping important functionality in place. This reaction is traditionally catalysed by high-valent oxo-rhenium species. Recent research into heterogeneous rhenium-based catalysts for DODH demonstrates their ability to rival and in some cases surpass their homogeneous counterparts. Furthermore, catalysts based on the metals molybdenum and vanadium show great potential as inexpensive alternatives to rhenium catalysts. In this Minireview, we detail the recent developments within the field of DODH with particular emphasis on discoveries outside the realms of rhenium.

Preparation of Highly Active Monometallic Rhenium Catalysts for Selective Synthesis of 1,4‐Butanediol from 1,4‐Anhydroerythritol

“…[1, 6, 7] Hydrogenolysis is a selective oxygen removal method, which is often used to break the C−O bond in sugar alcohols, however, the selectivities to target products are difficult to control, especially when the substrates are polyols such as erythritol or sorbitol . Deoxydehydration (DODH) is an effective process to reduce the oxygen content in biomass‐derived compounds by simultaneously removing the vicinal OH groups to form C=C bonds . In combination with C=C hydrogenation, DODH can simply remove vicinal OH groups from the substrate .…”

Valorization of Biomass‐derived Small Oxygenates: Kinetics, Mechanisms and Site Requirements of H2‐involved Hydrogenation and Deoxygenation Pathways over Heterogeneous Catalysts

“…and the identity of the RDS, which undoubtedly depend on the nature of the reductant and the reactivity of the diol . Some mechanistic issues have been discussed in recent reviews and perspectives, with an emphasis on homogeneous systems ,,…”

Single‐Site Molybdenum Catalyst for the Synthesis of Fumarate

“…Molybdenum based catalysts are the best and versatile catalysts of many industrially important reactions, such as polymerization reactions, olefin epoxidation and olefin metathesis . Recently, inorganic Mo‐based catalysts and a few of organic Mo complex catalysts have been explored to catalyze didehydroxylation reactions of polyols . While most Mo species exhibit moderate performance to form olefin products, and high temperature in the range of 200–250 °C was normally required .…”