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A light-mediated CÀ Se bond coupling reaction of aryl halides with diselenides under mild photocatalyst-free conditions for preparing aryl selenoethers has been achieved. The transformation is charactered by readily available materials, mild conditions, broad substrate scope and high efficiency. A reasonable mechanism has been proposed based on the preliminary mechanistic investigation. The protocol is also suitable for forging CÀ S bond and CÀ Te bond by the use of disulfides and ditellurides.

This study describes a regioselective ortho,ortho′-diborylation of aromatic triazenes catalyzed by [Ir­(OMe)­(cod)]2 in near-quantitative yields without an additional ligand. Aromatic triazenes act as both substrates and ligands. The X-ray structures of 2a and 2p indicate that the monoborylation products could promote the occurrence of diborylation. The synthesized triazene-substituted diboronate esters could undergo a variety of transformations including directing group removal. One-pot sequential modification provides a short entry to densely functionalized arenes.

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An oxidation cross-linking modified cassava starch (AHS) with high thermal viscosity stability and good film-forming property was synthesized by oxidation cross-linking and amidation reaction，which used ammonium persulfate (APS) as the oxidant, hexamethylenetetramine (HMT) as the cross-linking agent and urea as an assistant. The results of Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (1H NMR) showed that compared with cassava starch, the strength of the hydroxyl peak on the AHS structure changed, and the strength of the intramolecular hydrogen bond decreased. The crosslinking agent HMT releases formaldehyde under heating conditions to crosslink oxidized starch. The auxiliary urea undergoes an amidation reaction to form amide bonds while adsorbing residual formaldehyde, improving the toughness of the AHS sizing film. When the APS usage is 0.4% (carboxyl content is 0.3024%), the HMT usage is 0.35% (sedimentation volume is 7.8mL), and urea usage exceeds 3%, the viscosity thermal stability of the AHS sizing agent is well (97.12%), and the elongation of the sizing film can reach 2.97%. Finally, The AHS sizing agent can improve the tensile properties and wear resistance of cotton yarn. This study overcomes the toxic substance emissions caused by traditional aldehyde crosslinking agents, improves the viscosity stability of the starch sizing agent, and provides a new approach to improving the viscosity thermal stability and film-forming properties of starch sizing agents.