【作者】 齐颖；

【导师】 John E. Reiner；

【作者基本信息】 天津大学 ， 药物化学， 2007， 硕士

【摘要】 在用于有机合成的众多过渡金属催化剂中,钯催化剂占有极为重要的地位。近来,二价钯催化反应以其高选择性、环境友好以及原子经济性等诸多优点成为研究热点。本文围绕二价钯催化的烯丙位重排反应展开,主要内容包括以下三部分:第一部分,本文深入研究了以N-对甲苯磺酰(Ts)胺基甲酸烯丙酯为底物,在二价钯催化下的重排反应,讨论并精细优化了反应条件,扩展了底物范围。实验表明,底物结构越复杂反应条件越苛刻;催化剂用量影响不大;卤盐必需且过量;碱对反应基本上无影响;溶剂据温度要求不同可逐级选用四氢呋喃、1,4-二氧六环及N,N-二甲基甲酰胺;反应温度随底物结构复杂程度逐渐升高。此外,反应中意外发现了环合副产物。第二部分,本文将该方法论扩展至以N-无保护基、N-苄氧羰基(Cbz)以及N-叔丁氧羰基(Boc)取代的胺基甲酸烯丙酯为底物的,二价钯催化重排反应,实验表明,N-无保护基底物不发生重排反应,而后两者取得预期结果。在一、二部分工作成果的基础上及参考文献报道的类似机理,本文提出了倾向性机理,并针对环化副产物的形成提出探索性机理。第三部分,本文将该方法论扩展至以对甲苯磺酰胺基甲酸环丙酯为底物的重排反应研究,但由于底物的不稳定性,无法得到重排产物。此外,本文还尝试了其他过渡金属催化剂,初探了在铑催化下的烯丙位重排反应。更多还原

【Abstract】 Among the numerous transition metal catalysts, Palladium possess extremelyimportant status. Recently, palladium(Ⅱ)－catalyzed reaction has been widely studiedfor its high selectivity, environmental friendship, atomic economy, etc. In this paper,Palladium(Ⅱ)－catalyzed allylic rearrangement reaction is described. And the contentincludes mainly three aspects as follows:Firstly, palladium(Ⅱ)－catalyzed allylic rearrangement reaction, in which a seriesof allylic N－tosyl carbamates were used as the substrates, has been deeply studied.To optimize the reaction conditions, the main factors are widely discussed and thesubstrates were extended. The results are as follows: Conditions will be stricter if thestructure is more complicated; The amount of catalyst doesn’t impact the reactionvery much; Halide salt is necessary and should be excessive; Base doesn’t impact thereaction; THF, 1,4－dioxane, DMF as preferred solvents fit different reactivetemperatures. Besides, cyclized byproduct was discovered beyond our imagination.Secondly, the applications of this methodology were extended to many otherkinds of substrates, such as (1) allylic carbamate, (2) N－Cbz or (3) N－Boc allyliccarbamate. It indicated that substrate (1) couldn’t be rearranged. However, substrates(2) and (3) obtained the rearranged products as expectation.Based on the previous work and proposed mechanisms according to somereferences, the tendencious mechanism was chosen, and the formation mechanism ofthe cyclized byproduct was also explored.Finally, this methodology was extended to N－Tosyl cyclopropylmethylcarbamates rearrangement reseach. But because of the unstability of the startingmaterial, the rearranged product couldn’t be obtained. In addition, another kind oftransition metal－rhodium was also tried and obtained some good results.更多还原