Selectivities in the 1,3-dipolar cycloaddition of nitrile oxides to dicyclopentadiene and its derivatives
作者:Irishi N.N Namboothiri、Namrata Rastogi、Bishwajit Ganguly、Shaikh M Mobin、Miriam Cojocaru
DOI:10.1016/j.tet.2003.12.026
日期:2004.2
chemo- and stereoselectivity as in the case of dicyclopentadiene, exhibits complete regioselectivity as well providing a single isomer in good yield. The Influence of remote substituents, including sterically ‘sterile’ ones, on the regioselectivity has also been investigated using 8-hydroxy and 1-keto derivatives of dicyclopentadiene. These experimental observations have been investigated through gas phase
由醛肟和硝基烷烃生成的腈的1,3-偶极环加成反应成二环戊二烯,具有完全的化学和立体选择性。偶极子的进近只发生在exo上-双环庚烷部分的表面,以约55:45的比例提供区域异构体的混合物。另一方面,除了在二环戊二烯的情况下表现出化学和立体选择性之外,丁二烯环氧化物加成至二甲基二环戊二烯二羧酸酯(噻吩酸酯)的过程中,除了具有化学选择性和立体选择性外,还具有完全的区域选择性,并且可以提供单一异构体且收率很高。还已经使用二环戊二烯的8-羟基和1-酮衍生物研究了包括空间“无菌”取代基在内的远程取代基对区域选择性的影响。这些实验观察已通过气相和溶剂模型MO计算对半经验(PM3)和混合从头算DFT理论水平的过渡态几何进行了研究。