vinyl dichlorides and electron deficient amides as the starting material is described. In the absence of transition-metal catalyst, the reaction proceeds under mild reaction conditions in open air and thus rendering a convenient operation. This strategy is not only suitable for both terminal and internal ynamide synthesis but also amenable for large-scale preparation. Broad substrate scopes with respect
A novel method for the synthesis of α-amino alkenyl-substituted hydrazone derivatives was disclosed through silver-catalyzed reaction of sulfonyl hydrazones with ynamides. The present method features mild conditions, highstereoselectivity and good yields. The proposed mechanism involves silver-mediated generation of a keteniminium ion intermediate to facilitate the stereoselective addition of hydrazones
通过银催化磺酰与乙酰胺的反应,公开了一种合成α-氨基烯基取代的derivatives衍生物的新方法。本方法具有温和的条件,高的立体选择性和良好的收率。所提出的机理涉及银介导的酮亚胺离子中间体的产生,以促进在K 2 CO 3存在下立体选择性地添加,而在当前条件下不能构建吡唑环。
Borane-Catalyzed Selective Hydrosilylation of Internal Ynamides Leading to β-Silyl (<i>Z</i>)-Enamides
作者:Youngchan Kim、Ramesh B. Dateer、Sukbok Chang
DOI:10.1021/acs.orglett.6b03485
日期:2017.1.6
We have developed a borane-catalyzed regio- and stereoselectivehydrosilylation of internal ynamides for the first time. The scope of ynamide substrates and silane reactants was broad undermild reaction conditions, affording synthetically versatile β-silyl (Z)-enamide products. The observed stereoselectivity was reasoned to be due to the β-silicon effect on a postulated ketene iminium intermediate
Treatment of N-(1-alkynyl)amides and 1-alkynyl sulfides with diphenyldithiophosphinic acid affords (E)-ketene N,S-acetals and S,S-acetals, respectively. The addition reactions proceed in syn fashio...
A formal [3 + 2] cycloaddition between ynamides and unprotected isoxazol-5-amines has been developed in the presence of catalytic AgNTf2 in an open flask. By the protocol, a variety of functionalized 5-amino-1H-pyrrole-3-carboxamide derivatives can be obtained in up to 99% yield. The reaction mechanism might involve the generation of an unusual α-imino silver carbene intermediate (or a silver-stabilized