Heterogeneous Sodium‐Manganese Oxide Catalyzed Aerobic Oxidative Cleavage of 1,2‐Diols

Abstract

The aerobic oxidative cleavage of 1,2-diols using aheterogeneous catalyst only based on earth-abundant metals manganese and sodium is reported for the first time.T his reusable catalyst cleaves av ariety of substrates into aldehydes or ketones with high selectivity.T he reaction requires small catalytic loadings and is performed under mild conditions using ambient pressure O 2 or air as the oxidant while producing water as the only by-product. Mechanistic investigations reveal am onodentate,t wo-electron oxidative fragmentation process involving aM n IV species.T he eco-friendly, innocuous catalyst is compatible with aw ide range of functional groups and conditions,making it highly competitive with classical reagents,such as periodic acid or lead tetraacetate,as apreferred method for activated 1,2-diols.

Teaching Atom Economy and E-Factor Concepts through a Green Laboratory Experiment: Aerobic Oxidative Cleavage of meso-Hydrobenzoin to Benzaldehyde Using a Heterogeneous Catalyst

“…In our previous report, the E-factor of Na-MnOx protocol can reach 0.8 under optimized conditions . The Malaprade route displays the highest E-factor due to the excessive solvent for a small quantity of meso -hydrobenzoin that was used.…”

“…The 12 Principles of Green Chemistry provide comprehensive guidelines to chemists to design greener products and processes and have been made into countless lesson plans to integrate into undergraduate lectures and laboratory exercises. , Whereas many of these works explore safer chemical design, toxicity, and the use of renewable resources, the use of heterogeneous catalysts deserves more attention because it plays an important role in manufacturing platform chemicals . The practice of heterogeneous catalysis using an alternative synthetic strategy, such as aerobic catalysis, microwave-assisted synthesis, and electrocatalysis, has drawn much attention to the renewable feedstock community for their unique abilities to transform chemicals under mild conditions. − About 80% of the industrial chemical synthesis relies on heterogeneous catalysis for bulk chemical production, whereas homogeneous catalysis is more common for fine chemical syntheses, especially in small-volume chemistry such as pharmaceutical manufacturing. , Heterogeneous catalysis is essential to green chemistry and sustainability. − Heterogeneous catalysts can be reactivated conveniently through a simple chemical or heat treatment and, more importantly, can be removed or recovered easily by filtration, saving a countless amount of solvent used for separation. Crumbie reported a heterogeneous chemical transformation, but the reaction would require a stoichiometric quantity of chromium oxide .…”

“…A green protocol to achieve the cleavage of activated diols using an earth-abundant metal oxide, sodium-doped porous sodium manganese oxide (Na-MnOx), was recently reported by Anastas et al , The protocol is highly selective toward cleaving vicinal diols that are adjacent to an aromatic ring (a.k.a. activated diols) and requires a very low catalyst loading at 1 mol % relative to the substrate.…”

Putting Waste to Work: The Demonstrative Example of Pyrite Quarry Effluents Turned into Green Oxidative Catalysts

“…Recently, our group has developed two original methods for the aerobic oxidative cleavage of 1,2-diols with polymetallic catalysts prepared from Mn hyperaccumulating plants. 12,42 We wished to apply our new Pyr-Mn 2 catalyst derived from pyrite quarrying in oxidative cleavage reactions, to show the compatibility of the catalyst with different conditions and demonstrate its values as powerful synthetic tools.…”

Synergistic Bimetallic Pd–Pt/TiO2 Catalysts for Hydrogenolysis of Xylitol with In Situ-Formed H2

“…At present, hydrogenolysis of xylitol is often conducted in the presence of externally added H 2 (>4 MPa) in order to facilitate C–O and C–C bond cleavage. − Noble metal catalysts − such as Ru and Pt have been extensively studied for hydrogenolysis of xylitol to EG and 1,2-PDO using Ca­(OH) 2 and CaO as basic promoters, while non-noble Ni and Cu catalysts exhibit good chemoselectivity in C–O bond cleavage, although activity for C–C bond rupture is low. ,, Sun and Liu studied Ru catalysts supported on carbon for xylitol conversion in the presence of Ca­(OH) 2 , with a TOF value of 184.4 h –1 (1,2-PDO selectivity: 25.0% and EG selectivity: 32.4%) at 200 °C and 4 MPa H 2 pressure . Rivière et al.…”