Exploiting catalytic carbonyl-olefin metathesis is an ongoing challenge in organic synthesis. Reported herein is an FeCl3 -catalyzed ring-closing carbonyl-olefin metathesis. The protocol allows access to a range of carbo-/heterocyclic alkenes with good efficiency and excellent trans diastereoselectivity. The methodology presents one of the rare examples of catalytic ring-closing carbonyl-olefin metathesis. This process is proposed to take place by FeCl3 -catalyzed oxetane formation followed by retro-ring-opening to deliver metathesis products.

Selective CÀOb ond cleavagei so fh igh interest for moderno rganic synthesis. As trategy for selective allylic CÀOb ond cleavage using ethyl salicylate as ad irecting leaving group has been developed. The reactioni si nitiated by the chelation of the ortho-ester phenolic group with iron catalyst. The p-allyl iron intermediate is generated and reacts with Grignardr eagents to give the allylic substitution products. The excellent selectivity of CÀO bond cleavage is achieved in multiple allylic CÀOb ondcontaining substrates with the aid of the salicylate-directed strategy.

Transition metal-catalyzed allylic substitution reactions have evolved as versatile and powerful tools for organic synthesis. 1 Active allylic substrates bearing halides, acetates, carbonates, etc. as leaving groups are commonly used in allylic substitution reactions. The development of allylic substrates involving readily

The synthesis of new type furan-based compounds other than 5-hydroxymethylfurfural from glucose is a very attractive yet underexploited strategy. We report here a catalytic conversion of glucose with acetylacetone (acac)...

Lignin is a potential renewable raw material for synthesis of aromatic molecules and materials. Particularly, Kraft-type lignins are abundantly available as a byproduct of wood and paper industries. Currently, there are practically no valuable products made using this highly complex polymer. Within this work, we have investigated the straightforward, high-yield depolymerization of two different technical lignins (Indulin AT and alkaline lignin) using only a mixture of green short-chain (C1–C3) alcohols and water as solvents. As shown here, at a temperature of 220 °C, autogenous pressure, and isopropanol/water as a co-solvent medium, it is possible to cleave Kraft lignin without char-forming side reactions. The obtained so-called “light” oil contains guaiacol-based monomeric units of 23 wt % yield together with liquid oligomers of 13 wt % yield combining liquid–liquid and solid–liquid extraction. Two-dimensional nuclear magnetic resonance analysis of lignin residues showed that the isopropanol/water treatment caused a marked breakdown of the intermolecular β–O–4 and β–β bonds; thus, the depolymerization produced monomers and lignin residues with lower molecular weight. The results suggested a synergistic effect between isopropanol and water. No sign of repolymerization reactions could be observed with this process.