Hypervalent iodine(<scp>iii</scp>)-promoted N-incorporation into N-aryl vinylogous carbamates to quinoxaline diesters: access to 1,4,5,8-tetraazaphenanthrene
作者:A. Sagar、Shinde Vidaycharan、Anand H. Shinde、Duddu S. Sharada
DOI:10.1039/c6ob00447d
日期:——
A novel oxidative N-incorporation strategy for synthesis of quinoxaline diesters under metal-free conditions is described for the first time. The mild reaction conditions allow for this transformation via the formation of two C(sp2)–N bonds utilizing cheaply available NaN3 as the N-atom source. N-Aryl vinylogous carbamates in this study undergo azidation at enamino C(sp2)–H selectively. The robustness
l-Proline-catalyzed synthesis of highly functionalized multisubstituted 1,4-dihydropyridines
作者:Huanfeng Jiang、Ronghuan Mai、Hua Cao、Qiuhua Zhu、Xiaohang Liu
DOI:10.1039/b914659h
日期:——
Highlyfunctionalized multisubstituted 1,4-dihydropyridines 5 have been concisely synthesized in moderate to good yields viaL-proline-catalyzed one-pot multicomponentreactions (MCRs) of alkynoates or alkynones 1, amines 2, β-dicarbonyl compounds 3 and aldehydes 4 under mild conditions. The MCR process involves hydroamination/Knoevenagel condensation/Michael-type addition/intramolecular cyclization
The practical synthesis of polysubstituted tetrahydropyrimidines 4 from but-2-ynedioates 1, amines 2, and formaldehyde 3 through a domino process of one-pot multicomponent reactions (MCRs) and the detailed mechanistic studies are described. The MCRs were performed under extremely mild reaction conditions and offered the desired products in excellent yields. The detailed studies on the mechanism of
An eco-friendly sequential catalyst- and solvent-free four-component stereoselective synthesis of novel 1,4-pyranonaphthoquinones
作者:Balasubramanian Devi Bala、Stephen Michael Rajesh、Subbu Perumal
DOI:10.1039/c2gc35930h
日期:——
A series of novel highly functionalized 1,4-pyranonaphthoquinones has been synthesized stereoselectively from one-pot sequential reactions of anilines, diethyl acetylenedicarboxylate, 2-hydroxynaphthalene-1,4-dione and benzaldehydes under microwave irradiation. This solvent- and catalyst-free transformation affording biologically relevant heterocycles presumably involves two Michael additions, aldol condensation and annulation reactions.