炔丙型硫Ylide环丙烷化反应及其立体选择性  

Cyclopropanation Reaction and Diastereoselectivity of Propargyl Sulfur Ylide with Acrylates

作　　者：刘文剑[1] 路慧哲[1] 肖玉梅[1] 王明安[1] 杜凤沛[1] 付滨[1] 李楠[1] 覃兆海[1] 

机构地区：[1]中国农业大学理学院,北京100193

出　　处：《高等学校化学学报》2009年第7期1357-1360,共4页Chemical Journal of Chinese Universities

基　　金：国家"八六三"计划(批准号:2006AA10A213)资助

摘　　要：炔丙型硫Ylide与丙烯酸酯的反应是一个多反应竞争的复杂反应,通常环丙烷化产物收率很低.本文通过对反应底物的优化,成功获得了高收率、高选择性的反式环丙烷化产物.同时利用Gaussian 03程序,选择密度泛函BHHLYP方法,6-31G**基组对反应路径及过渡态模型进行了计算,进而采用密度泛函理论中的B3LYP方法,选择6-31G**基组,对顺、反式产物的热稳定性进行了分析,明确了该反应的高非对映选择性是由过渡态的能量差异和产物的热稳定性两个因素共同决定的,而过渡态的能量差异可以归于分子内弱的立体电子效应的不同.The cyelopropanation of propargyl sulfur Ylide with acrylate usually gave poor yield because of several competing reactions such as [2,3]-σ atropic rearrangement were also involved in this system. In our research, a higher yield（75% ） and high diastereoselectivity（96% d. e. ） for trans-2-ethynyl cyclopropane carboxylate were obtained by changing the structure of sulfur ylide and optimizing the reaction conditions. The mechanism and diastereoseleetivity of the reaction were studied via the density functional theory method. High selectivity toward trans cyclopropanes are predicted on the basis of the relative activation energies of diastereomeric torsional transition states and the thermodynamic satbility of products. The energy differences between these transition states could be rationalized with the help of weak intramolecular stereoelectronic interactions.

关 键 词：环丙烷化反应 炔丙型硫Ylide Trans-2-乙炔基环丙烷羧酸酯 密度泛函理论 过渡态 

分 类 号：O624.5[理学—有机化学] O641.121[理学—化学]