Novel One-Pot Synthesis of Dihydroacenaphtho[1,2-f][1,3]oxazepines via 1,4-Dipolar Cycloaddition Reaction
摘要:
A facile three-component reaction involving 3-alkyl(aryl)imidazo[1,5-a]pyridines 7a-g, dimethyl acetylenedicarboxylate 2 (DMAD) and acenaphthene-1,2-dione 5 led to the construction of the respective dihydroacenaphtho[1,2-f][1,3]oxazepine-10,11-dicarboxylates 10a-g in fair yields. Structures of the latter tetracyclic adducts, are based on NMR and MS spectral data and confirmed by single-crystal X-ray diffraction analysis for compound 10a. Most logically, the reaction proceeds via initial formation of the relevant diastereomeric spiro[1,3]oxazine-1,4-dipolar cycloadducts 12, 13 which then suffer skeletal rearrangement leading to the respective acenaphtho[1,2-f][1,3]oxazepines 10a-g.
An efficient method for N-acylation of amides is described using a pyridine ring as the internal nucleophilic catalyst to give imides in moderate to excellent yields. The methodology provides a facile, air insensitive, and environmentally friendly route to form diversified imide scaffolds, which exist widely in natural products and biologically active materials.
Cobalt-catalyzed C H activation of N-carbamoyl indoles or benzamides with maleimides: Synthesis of imidazo[1,5-a]indole- or isoindolone-incorporated spirosuccinimides
作者:Murong Xu、Yang Yuan、Ye Wang、Yuanyang Mu、Huihui Xie、Yanzhong Li
DOI:10.1016/j.tetlet.2021.152872
日期:2021.4
A cobalt-catalyzed CH activation/cyclization of N-carbamoyl indole/benzamides with maleimides assisted by pyridinylmethylamine under mild reaction conditions is described. The synthetic strategy was developed to access imidazo[1,5-a]indole-/isoindolone-incorporated spirosuccinimides with a broad substrate scope and high regiospecificity.
Rh(<scp>i</scp>)-Catalyzed [3+2] annulation reactions of cyclopropenones with amides
作者:Akira Haito、Naoto Chatani
DOI:10.1039/c9cc02397f
日期:——
Rh(I)-Catalyzed [3+2] annulation reactions of cyclopropenones with amides are reported. The reaction provides a direct approach for producing highly substituted α,β-unsaturated γ-lactam derivatives. The presence of an N(sp2) atom in the N-alkyl group of the amide, such as the 2-pyridinylmethyl or 8-aminoquinonyl group, is essential for the success of the reaction.