Competition Studies in Alkyne Electrophilic Cyclization Reactions
作者:Saurabh Mehta、Jesse P. Waldo、Richard C. Larock
DOI:10.1021/jo802196r
日期:2009.2.6
toward alkyneelectrophiliccyclizationreactions has been studied. The required diarylalkynes have been prepared by consecutive Sonogashira reactions of appropriately substituted aryl halides and competitive cyclizations have been performed using I2, ICl, NBS and PhSeCl as electrophiles. The results indicate that the nucleophilicity of the competing functional groups, polarization of the alkyne triple
已经研究了各种官能团对炔烃亲电环化反应的相对反应性。所需的二芳基炔已通过适当取代的芳基卤化物的连续 Sonogashira 反应制备,并使用 I 2、ICl、NBS 和 PhSeCl 作为亲电子试剂进行竞争性环化。结果表明,竞争官能团的亲核性、炔烃三键的极化和中间体的阳离子性质是决定这些反应结果的最重要因素。
Regio- and Stereoselective Electrophilic Cyclization Approach for the Protecting-Group-Free Synthesis of Alkaloids Lennoxamine, Chilenine, Fumaridine, 8-Oxypseudoplamatine, and 2-<i>O</i>-(Methyloxy)fagaronine
作者:Tuanli Yao、Zhen Guo、Xiujuan Liang、Lihan Qi
DOI:10.1021/acs.joc.8b02154
日期:2018.11.2
protecting-group-free synthesis of alkaloids lennoxamine, chilenine, fumaridine, 8-oxypseudoplamatine, and 2-O-(methyloxy)fagaronine is reported. The core isoindolin-1-one and isoquinolin-1-one structures were built by a silver-catalyzed regio- and stereoselective cyclization of methyl 2-alkynylbenzimidates. The regioselectivity of cyclization was achieved by utilizing the intrinsic functionality of alkaloids.