尽管人们对具有γ-氨基羰基基序的有机化合物产生了广泛的兴趣,但其合成策略的报道却很有限。在此,我们描述了一种温和有效的方法,以亲电子 N 中心自由基作为关键中间体,对不饱和烯酮进行位点选择性酰胺化。二烯醇化物与N-氨基吡啶鎓盐的光催化插烯反应得到γ-酰胺基羰基化合物。该工艺产率高、可扩展,并且可以使用多种不饱和 α,β-不饱和羰基化合物(包括生物相关化合物)作为起始材料。
acyclic: The first catalytic, enantioselective, vinylogous Michael reaction of linear, acyclic dienol silyl ethers was achieved. The reaction, based upon the principle of iminium ion catalysis, delivered 1,7‐dioxo compounds in one step with good yields, complete regio‐, and excellent enantioselectivity. γ‐Substituted dienol silyl ethers furnished products with two new stereogenic centers with good diastereoselectivity
Brønsted Acid Catalyzed Synthesis of Functionalized 1,4- and 1,6-Dicarbonyl Monosilyl Enol Ethers under Operationally Practical Conditions
作者:Joshua A. Malone、Joshua P. Van Houten、Moshood O. Ganiu、Binod Nepal、Rendy Kartika
DOI:10.1021/acs.joc.7b01687
日期:2017.10.6
for the concise synthesis of functionalized 1,4- and 1,6-dicarbonyl-derived monosilyl enol ethers via ionization of α′-hydroxy silyl enol ethers to generate unsymmetrical silyloxyallyl cations that were subsequently captured by TBS silyl enolates. These transformations were efficiently performed in acetonitrile at room temperature by employing pyridinium triflate as a catalyst. Our new reaction conditions