Aihua Zhou

Diversity-oriented syntheses: coupling reactions between electron-deficient olefins and aryl aldehydes via C(sp2)-H functionalization.

A diversity-oriented syntheses by coupling three electron-deficient olefins (vinyl sulfonamides, methacrylamides, and methyl acrylates, respectively) with aryl aldehydes via C(sp(2))-H functionalization were reported. These reactions gave four different skeletal products respectively under environment-friendly and mild conditions. All these reactions are highly regioselective and effective, very suitable for the preparation of synthetic building blocks and compound library, the results will enrich current coupling chemistry of olefins with aldehydes and can be applied to other chemistry areas as well.

Tandem reactions of 1,3-diacid chlorides with 2-methylimidazoline and 2-methyl-1,4,5,6-tetrahydropyrimidine: one-pot synthesis of 1,8-naphthyridinetetraones.

The reactions of 2-methylimidazoline and 2-methyl-1,4,5,6-tetrahydropyrimidine with 1,3-diacid chlorides, in the presence of Et3N in refluxing MeCN give highly functionalized potentially bioactive 1,8-naphthyridinetetraones. 2-Methylimidazoline and 2-methyl-1,4,5,6-tetrahydropyrimidine can be viewed as tridentate nucleophiles which give four consecutive tandem nucleophilic attacks on electrophiles.

Parallel Syntheses of Eight-Membered Ring Sultams via Two Cascade Reactions in Water

From vinyl sulfonamides as precursors to vinyl sulfonamide epoxides, two cascade reaction protocols were developed to synthesize eight-membered ring sultams in water. These protocols employ intermolecular Michael addition by NaOH or NaHS in water, followed by rapid proton transfer and intramolecular 8-endo-tet epoxide ring-opening to give medium-size sultams selectively in one-pot. Novel core structures and high synthetic efficiency make these cascade reactions highly suitable for sultam library production. Both reactions proceeded well and afforded the respective sultams in good yields under environmentally friendly conditions.

Making Flavone Thioethers Using Halides and Powdered Sulfur or Na2S2O3

The method for constructing C-S bonds is very important in organic synthesis. Here a new sulfenylation method to generate flavone thioether derivatives was developed by employing aromatic or alkyl halides, S powder and Na2S2O3 as reactants. Good yields of regioselective Calkyl-S and Caryl-S-substituted flavones were generated under relatively environmentally friendly and simple conditions. This method might be potentially applicable to large scale production, and it enriches current sulfenylation methods.