TBAI-Catalyzed Oxidative Coupling of Benzyl Ketones to Synthesize 2,3-Diaryl-1,4-Diketones in Water

Allylation of cellulose microfibers for hydrosilylation with various hydrosilanes and hydrosiloxanes, and their application in corn-starch-mimosa tannin (CSMT) adhesive to improve particleboard properties

Recently, Cellulose microfibers (CMF) have garnered significant attention due to their renewability, biodegradability, and unique properties such as high aspect ratio, low density, high strength, stiffness, and distinctive optical properties. These characteristics have been highlighted in publications worldwide. However, the structure of CMF is difficult to access with solvents, limiting its dissolution in common organic solvents. The synthesis of CMF-siloxane or CMF-silane hybrid materials from cellulose generally involves several reactions steps, and therefore catalysts. The allylation of CMF is catalyzed by the phase-transfer catalyst tetrabutylammonium bromide (TBAB), which enables the combination of CMF with allyl. This is followed by a hydrosilylation reaction catalyzed by Karstedt's catalyst, based on platinum (0), to combine the hydrophilic allylated CMF with hydride-terminated hydrophobic hydrosilane or hydrosiloxane. Environmentally friendly particleboards were developed using bio-based adhesives composed of corn-starch and Mimosa tannin (CSMT) mixtures. These mixtures included 4, 6, 8, and 10 wt% of CMF, allylated CMF and silylated CMF. The mechanical and physical properties of particleboards, such as modulus of elasticity (MOE), modulus of rupture (MOR), internal bond strength (IB), surface soundness (SS), water absorption (WA) and thickness swelling (TS) were determined.

Synthesis of Novel 1,4-Diketone Derivatives and Their Further Cyclization

One of the important reactions to obtain a new carbon-carbon bond is the Stetter reaction, which is generally via a nucleophilic catalyst like cyanide or thiazolium-NHC catalysts. In particular, 1,4-diketones with very functional properties are obtained by the Stetter reaction with the intermolecular reaction of an aldehyde and an α,β-unsaturated ketone. In this study, we synthesized new derivatives (substituted arenoxy) of 1,4-diketone compounds (2a-2n) with useful features by a new version of the Stetter reaction method. In our work, arenoxy benzaldehyde derivatives with different structures as the Michael donor and methyl vinyl ketone as the Michael acceptor were used for the intermolecular Stetter reaction. The reaction was catalyzed by 3-benzyl-5-(2-hydroxyethyl)-4-methylthiazolium chloride (3b), using triethylamine for the basic medium and dimethyl sulfoxide as the solvent. As a result, some novel arenoxy-substituted 1,4-diketones were gained with good yields at room temperature within 24 h through an intermolecular Stetter reaction. In addition, new furan and pyrrole derivatives were prepared by performing the cyclization reaction with one of the obtained new diketone compounds.

Regio- and diastereoselective synthesis of unsymmetrical 1,4-diketone-derived (Z)-monosilyl enol ethers via siloxyallylpotassium intermediates

This paper describes the regio- and diastereoselective synthesis of unsymmetrical 1,4-diketone-derived (Z)-monosilyl enol ethers from 1-arylallyloxysilanes and Weinreb amides using (trimethylsilyl)methylpotassium as a base. The metalation of 1-arylallyloxysilanes to generate siloxyallylpotassiums is the key step in this transformation. The products can be transformed into diverse α-monofunctionalized unsymmetrical 1,4-diketones.

Iron-Catalyzed Oxidative α-Amination of Ketones with Primary and Secondary Sulfonamides

We report the iron-catalyzed α-amination of ketones with sulfonamides. Using an oxidative coupling approach, ketones can be directly coupled with free sulfonamides, without the need for prefunctionalization of either substrate. Primary and secondary sulfonamides are both competent coupling partners, with yields from 55% to 88% for deoxybenzoin-derived substrates.