Department of Chemistry, Florida Atlantic University, Boca Raton, FL 33431, USA.
Angew Chem Int Ed Engl. 2011 Aug 29;50(36):8338-41. doi: 10.1002/anie.201101090. Epub 2011 Jul 15.
Cyclic addition of a hydrazine nitrogen to unactivated alkynes catalyzed by non-metals. Starting from readily accessible γ-silyl allenyl esters, β-alkynyl hydrazines are prepared in one step and subsequently undergo unprecedented cyclization reactions in the presence of ammonium and phosphonium catalysts leading to dehydro-azaproline products. These heterocycles are also produced in high enantiomeric excesses using chiral ammonium phase transfer catalysts via a kinetic resolution pathway.
非贵金属催化的肼氮对未活化炔烃的环加成反应。从易得的γ-硅基烯丙基酯出发,一步制备β-炔基腙,然后在铵盐和鏻盐催化剂的存在下,发生前所未有的环化反应,得到脱氢-氮杂脯氨酸产物。这些杂环化合物也可以使用手性季铵盐相转移催化剂通过动力学拆分途径以高对映过量值得到。