金催化1，n-烯炔与重氮化合物[2+2+m]环加成反应研究

Gold-catalyzed intramolecular cycloisomerization of 1, n-enynes (n=5-7) have attracted much attention of organic chemists in recent years. However, examples of gold catalyzed 1,n-enyne [2+2+m](n=5-7, m=2-3)cycloaddition reaction are seldom documented. From a mechanistic point of view, an alkenyl gold carbocation intermediate II, in situ generated in the process of the gold-catalyzed enyne cycloisomerization, could also behave as the dipolar reactants in gold catalyzed [2+2+m] cycloaddition of 1,n-enynes (n=5-7) with suitable dipolarphiles. Considering the difficulties existed in this type of reactions (competitive intramolecular enyne cycloisomerization and intermediate I's competitive reaction), it's great challenge to develop new type of enyne [2+2+m] cycloaddition in gold catalyzed condition. After a series of experiments, we have deveoped a new type of gold catalyzed 1,6-enyne [2+2+1] cycloaddition reaction by using diazo ester as the one carbon unit dipolarphile. Notably, this is first examples of utilizing diazo ester as the dipolarphile in dipolar cycloaddition reaction. Based on this result, we want extend this study to two type of reactions: 1, gold catalyzed [2+2+1] cycloaddition of 1,n-enynes (n=5-7) using diazo compound as dipolarphile; 2, gold catalyzed [2+2+3] cycloaddition of 1,n-enynes (n=5-7) using vinyl diazo compound as dipolarphile. Then, we want further explore asymmetric 1,n-enynes (n=5-7) [2+2+m] (m=1,3) cycloaddition reaction by using various types of chiral gold catalysts. At last, exploration upon the synthetic application of this new type of reaction will be performed for the preparation of some bi- and tricyclic natural products.

本课题主要研究金催化1，n-烯炔与重氮化合物的[2+2+m]（n=5-7，m=1，3）环加成反应。金催化烯炔[2+2+m]环加成反应与其他过渡金属催化的反应不同，关键步骤为亲偶极子（dipolarphile）捕获含烯基金碳正离子（dipole）的反应过程。针对该类反应面临的问题，及之前研究工作的局限，本课题提出了拓展新的亲偶极子及发展新的环化反应类型的设想。在取得初步研究成果-金催化1，6-烯炔与重氮酯的[2+2+1]环加成反应的基础上，进一步开展研究，计划探索金催化分子内，分子间1，n-烯炔与重氮化合物的[2+2+m]（n=5-7，m=1，3）的环加成反应研究，以合成多种类型的双环/三环结构化合物；同时，合成新颖的手性金催化剂，实现烯炔与重氮化合物的不对称[2+2+m]反应过程；在这些研究的基础上，探索该类反应在类似结构天然产物的合成中的应用。

本课题主要研究金催化1，n-烯炔与重氮化合物的【2+2+m】环加成反应。反应的关键步骤为亲偶极子（dipolarphile）捕获烯炔环异构化中间体。本课题采用重氮酯作为一种新类型的亲偶极子（dipolarphile）捕获金催化1，n-烯炔的环异构化反应的中间体，通过一系列后续反应过程，实现金催化1，n-烯炔的多元环加成反应。项目批准了以后，我们主要发展了以下几种类型的环化反应：.1、 金催化1，6-双烯炔与重氮酯的分子间【2+4+1】环加成反应，得到5，7-双环化合物。.2、 卡宾银催化重氮酯与醛，缺电子炔（或烯）的分子间【2+2+1】环加成反应； .3、 轴手性双三唑卡宾金催化剂催化的联烯胺与烯烃的分子间不对称【2+2】环加成反应。