Synthesis of 2-Aza-1,3-butadienes through Gold-Catalyzed Intermolecular Ynamide Amination/C–H Functionalization
作者:Chao Shu、Cang-Hai Shen、Yong-Heng Wang、Long Li、Tao Li、Xin Lu、Long-Wu Ye
DOI:10.1021/acs.orglett.6b02267
日期:2016.9.16
A novel gold-catalyzed tandem intermolecular ynamide amination/C–H functionalization has been developed. A variety of highly functionalized 2-aza-1,3-butadienes can be obtained readily by utilizing this strategy. In addition, α-imino gold carbene intermediates are proposed in this amination reaction and with support by DFT (density functional theory) calculations.
Stereoselective Synthesis of (2<i>Z</i>)-2,4-Dienamides via NBS-Mediated Allyloxyl Addition–Claisen Rearrangement–Dehydrobromination Cascade Reaction of Ynsulfonamides
An NBS-promoted allyloxyl addition-Claisen reatrangement-dehydrobtomination cascade reaction has been developed. More than 20 substituted alkynylsulfonamides were reacted with allyl alcohols to generate (2Z)-2,4-dienamides in moderate to high yields. A mechanistic model has been proposed to account for the overall reaction sequence including the stereochemical outcome. Theoretical calculations suggested that a [3,3] sigmatropic rearrangement be the rate-limiting step.
Iron-Catalyzed Amidation of Alkynyl Bromides: A Facile Route for the Preparation of Ynamides
A facile route to obtain ynamides in high yields was described. The products were achieved through the iron-catalyzed C-N coupling reaction of amides with alkynyl bromides in the presence of 20 mol % of N,N'-dimethylethane-1,2-diamine (DMEDA).
Synthesis of Multisubstituted Enamides via Pd-Catalyzed Chloroallylation of Ynamides
An atom-economic approach to the regio- and stereoselective assembly of highly substituted enamides is described via the Pd-catalyzed chloroallylation of ynamides at room temperature, which offers a simple and practical alternative to the stereodefined multisubstituted enamides.