Co(III)-Catalyzed Coupling of Enaminones with Oxadiazolones for Imidazole Synthesis.

Appendage speciation-oriented synthesis, as opposed to the conventional wisdom of skeleton speciation-oriented synthesis, is reported herein, emphasizing the maximization of type-, position-, and configuration-variance of appendages. A Co(III) catalytic protocol in accordance with this synthetic modality has been established for the coupling of enaminones and oxadiazolones to imidazoles, allowing the achievement of full position-variance of appendages. This translates to an expanded reaction and structural development scope and can provide fertile ground for productive organic synthesis.

Synthesis of quinazolinones via Cp*Co(III)-catalyzed C-H functionalization of primary amides with oxadiazolones.

Multi-heteroatom heterocycle synthesis through direct C-H bond activation is methodologically appealing but synthetically challenging. An efficient double C-N bond formation sequence to prepare quinazolinones utilizing primary amides and oxadiazolones in a catalytic redox-neutral [CoCp*(CO)I2]/AgSbF6 system, where oxadiazolone could function as an internal oxidant to maintain the catalytic cycle, is reported. Amide-directed C-H bond activation and oxadiazolone decarboxylation are key to the success of this traceless, atom- and step-economic, and cascade approach for the construction of the quinazolinone skeleton.

Effect of Thermal Oxygen Aging Mode on Rheological Properties and Compatibility of Lignin-Modified Asphalt Binder by Dynamic Shear Rheometer.

Lignin is abundant in nature. The use of lignin in the asphalt pavement industry can improve pavement performance while effectively optimizing pavement construction costs. The purpose of this paper is to study the effect of lignin on the anti-aging properties of asphalt. Commercial lignin was selected to prepare a lignin-modified asphalt binder. The properties of lignin-modified asphalt were studied by rheological experiments. The high-temperature rheological properties of two kinds of base asphalt and modified asphalt samples with different contents of lignin under three conditions of original, rolling thin film oven (RTFO) aging, and pressure aging vessel (PAV) were tested and analyzed with temperature sweep, frequency sweep, and multiple stress creep recovery (MSCR) tests. By comparing the variation laws of evaluation indicators, such as complex shear modulus G*, phase angle δ, anti-aging index, cumulative strain, and viscous component Gv, we found that lignin could effectively improve the high-temperature stability of base asphalt, but it had a negative impact on the compatibility issues of base asphalt. Meanwhile, lignin played a filling role in the base asphalt, and the increase in viscosity was the fundamental reason for improving the high-temperature stability of the base asphalt. The research results indicated that lignin could effectively improve the anti-aging performance of asphalt and play a positive role in prolonging the service life of pavement.

Synthesis of 5H-Chromeno[2,3-d]pyrimidin-5-one Derivatives via Microwave-Promoted Multicomponent Reaction.

A microwave-promoted multicomponent reaction of 3-formylchromones, amines, and paraformaldehyde was achieved under catalyst-free and solvent-free conditions, delivering 5H-chromeno[2,3-d]pyrimidin-5-one derivatives in good to excellent yields via an unexpected annulation pathway, which further expanded the synthetic application of paraformaldehyde as a C1 building block.

Iodine(III) promotes cross-dehydrogenative coupling of N-hydroxyphthalimide and unactivated C(sp3)-H bonds.

Cross-dehydrogenative coupling reactions provide a method to construct new chemical bonds by direct C-H activation without any pre-functionalization. Compared to functionalization of a C-H bond α- to ether oxygen, α- to carbonyl, or at a benzylic position, functionalization of unactivated hydrocarbons is difficult and often requires high temperatures, a transition-metal catalyst, or a superstoichiometric quantity of volatile, toxic, and explosive tert-butylhydroperoxide. Here, a cross-dehydrogenative C-O coupling reaction of N-hydroxyphthalimide with unactivated alkanes, nitriles, ethers, and thioethers has been realized by using iodobenzene diacetate as the radical initiator. The current protocol enables efficient functionalization of unactivated hydrocarbons and nitriles through inert C(sp3)-H bond activation under mild reaction conditions. O-substituted NHPI derivatives are generated in good yields under metal-free conditions.

Design, synthesis and anticancer activity of naphthoquinone derivatives.

Basis on molecular docking and pharmacophore analysis of naphthoquinone moiety, a total of 23 compounds were designed and synthesised. With the help of reverse targets searching, anti-cancer activity was preliminarily evaluated, most of them are effective against some tumour cells, especially compound 12: 1-(5,8-dihydroxy-1,4-dioxo-1,4-dihydronaphthalen-2-yl)-4-methylpent-3-en-1-yl-4-oxo-4-((4-phenoxyphenyl)amino) butanoate whose IC50 against SGC-7901 was 4.1 ± 2.6 µM. Meanwhile the anticancer mechanism of compound 12 had been investigated by AnnexinV/PI staining, immunofluorescence, Western blot assay and molecular docking. The results indicated that this compound might induce cell apoptosis and cell autophagy through regulating the PI3K signal pathway.