1,4-Dipolar cycloadditions and related reactions

Synthesis of benzofused 1,4-azaborinols via [4 + 2] annulation strategy and its application in indole synthesis

The first general synthesis of benzofused 1,4-azaborinols via [4 + 2] annulation strategy and its application in indole synthesis.

One-pot four-component reaction for convenient synthesis of functionalized 1-benzamidospiro[indoline-3,4'-pyridines]

The one-pot four-component reaction of benzohydrazide (2-picolinohydrazide), acetylenedicarboxylate, isatins and malononitrile (ethyl cyanoacetate) with triethylamine as base catalyst afforded functionalized 1-benzamidospiro[indoline-3,4'-pyridines] in good yields. (1)H NMR spectra indicated that an equilibrium of cis/trans-conformations exist in the obtained products.

Synthesis of benzimidazole[2.1-b][1,3]oxazine spirooxindoles via three-component reaction of N-benzylbenzimidazole, acetylenedicarboxylates, and N-alkylisatins

The three-component reaction of N-benzylbenzimidazole, dialkyl acetylenedicarboxylate, and N-alkylisatins in tetrahydrofuran at room temperature afforded the novel functionalized benzimidazole[2.1-b][1,3]oxazine spirooxindoles in good yields. (1)H NMR spectra indicated that two diastereoisomers with a ratio of 1:3-1:6 exist in the obtained spirooxindole derivatives.

Four-component reaction of N-alkylimidazoles(N-alkylbenzimidazoles), dialkyl but-2-ynedioate, N-alkylisatins and malononitrile

Convenient synthesis of complex spirooxindolesviafour-component reactions ofN-alkylimidazoles(N-alkylbenzimidazoles), dialkyl but-2-ynedioate,N-alkylisatins and malononitrile.