We report a novel and practical one-pot Rh­(III)-catalyzed strategy to construct benzimidazo­[1,2-a]­quinolines from readily available imidamides and anthranils. The cascade reaction proceeds via a C–H amination–cyclization–cyclization process in ionic liquid without any additives and possesses simple operation, moderate-to-high yield, and broad substrate scope features, which will provide the reference for the construction of biologically active fused benzimidazoles.

In this study, the extraction of water-soluble polysaccharides from the seed coat of black soybean (BSCP) was investigated and optimized. A response surface methodology based on a Box-Behnken design (BBD) was used to optimize the extraction conditions as follows: extraction temperature, 100°C; ratio of water to material, 22.3 mL/g; and extraction time, 133.2 min. Under these conditions, the experimental yield of polysaccharides was 10.56%, which was consistent with the predictive yield. A novel galactomannan, BSCP-1, with a molecular weight of 7.55 × 105 Da determined by high-performance gel permeation chromatography, was isolated from the black soybean seed coat. Through gas chromatography-mass spectrometry analysis, BSCP-1 was identified as a galactomannan consisting of galactose, mannose and rhamnose in a molar ratio of 6.01:3.56:1.00. Cytotoxicity against the human gastric carcinoma cancer cell line was also determined.

A mild and recyclable protocol to synthesize 1,2-benzothiazines by Rh­(III)-catalyzed C–H activation/cyclization of NH-sulfoximines in ionic liquids with high yields is described. A broad substrate scope of NH-sulfoximines and coupling partners is applicable in this method without any base or acid additives. The catalytic system, namely, Cp*Rh­(III)/AgSbF6/[BMIM]­[PF6], still maintained good catalytic activity even after 10 cycles.

A mild cascade annulation of Co(III)-catalyzed N-chlorobenzamide with 2-acetylenic ketones at room temperature has been reported. This reaction sets N-Cl bond of N-chlorobenzamide as an internal oxidant, displaying broad functional group tolerance and excellent reverse selectivity of alkyne insertion under mild and safe conditions. The cascade reaction offers a straightforward and mild protocol to construct isoquinolones with high yields at room temperature.

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