摘要
以手性双噁唑啉2,2-(2,2′-4(S)苄-基-4,5-二氢噁唑啉基)丙烷为配体,研究了它与铜或锌的络合物对二苯基硝酮与富电子烯烃乙烯基乙醚的1,3-偶极环加成反应的催化效果,并考察了不同反应条件对催化效果和产物立体选择性的影响。研究结果表明,该手性金属催化剂能够较大程度地提高反应速度,其中铜络合物催化剂的反应速度提高280倍以上。催化剂对反应的立体选择性有明显的影响,使反应产物的endo/exo的比例逆转,但对反应的光学选择性影响较小。另外,还考察了4A分子筛对反应的影响。
The effect of the complexes of copper （Ⅱ） or zinc （Ⅱ） with 2,2 - bis[2,2′ -4（S） - benzyl -4,5 - di- hydrooxazole] propane catalysis on the 1,3 -dipolar cycloaddition reactions of diphynyl nitrone with electron -rich ethyl vinyl ether under various reaction conditions is determined. The results show that chiral bis （oxazoline） metal complexes accelerate the reaction rate greatly ; it is more than 280 times higher in the presence of copper complexes catalyst than in the absence of it. And there some effect of chiral metal catalysts on the stereoselectivity, thus the endo/exo selectivity of the reaction is reversed in the presence of catalysts, but the diastereoselectivity of the reaction is changed very little. The effect of 4A molecular sieves on the reaction is also discussed.
出处
《黑龙江大学自然科学学报》
CAS
北大核心
2007年第5期666-669,共4页
Journal of Natural Science of Heilongjiang University
基金
国家自然科学基金资助项目(20272011)
