N-Heterocyclic Carbene-Catalyzed Annulations of Enals and Ynals with Indolin-3-ones: Synthesis of 3,4-Dihydropyrano[3,2-<i>b</i>]indol-2-ones
作者:Yingyan Lu、Weifang Tang、Yu Zhang、Ding Du、Tao Lu
DOI:10.1002/adsc.201200716
日期:2013.2.1
Enal and ynal-derived α,β-unsaturated acylazoliums under N-heterocyclic carbene (NHC) catalysis have been applied for annulations with indolin-3-ones. The two reactions offer a direct and efficient access to functionalized 3,4-dihydropyrano[3,2-b]indol-2-ones in moderate to high yields, which may provide promising candidates for drug discovery.
在N-杂环卡宾(NHC)催化下,烯醛和依纳醛衍生的α,β-不饱和酰基acy已被用于吲哚3-3-酮的环化反应。这两个反应以中等至高收率提供了直接有效地获得官能化3,4-二氢吡喃并[3,2- b ]吲哚-2-酮的途径,这可能为药物发现提供有希望的候选者。
Synthesis of Diversified Pyrazolo[3,4-b]pyridine Frameworks from 5-Aminopyrazoles and Alkynyl Aldehydes via Switchable C≡C Bond Activation Approaches
cascade 6-endo-dig cyclizationreaction was developed for the switchable synthesis of halogen and non-halogen-functionalized pyrazolo[3,4-b]pyridines from 5-aminopyrazoles and alkynyl aldehydes via C≡C bond activation with silver, iodine, or NBS. In addition to its wide substrate scope, the reaction showed good functional group tolerance as well as excellent regional selectivity. This new protocol
Herein, we report a novel strategy for the regioselectivesynthesis of aromatic and heteroaromatic 2,3-dihydrooxazoles from 2-alkynyl-1,3-dithianes and nitrones. This method exploits the 1,3-dithiane umpolung, nucleophilic cycloaddition, and rearrangement processes to achieve the rapid assembly of dihydrooxazole molecules. The regioselective method is extremely mild, achieving complete conversion within