以膦烯酮为模板并用氮杂环卡宾来催化的合成磷杂环的研究

自从发现稳定的氮杂环卡宾（NHCs），它就一直是化学学科的研究热点。现在NHCs在有机金属催化、主族化学、和有机催化邻域等都得到了广泛的应用。近年来，由于合成技术的发展和实验表征技术的进步，磷化学研究的领域得到了很大的拓展。然而，高反应活性磷杂环的研究依然比较有限。对此本项目结合NHCs在催化邻域上的优势，对磷杂环的合成方法上提出了一种新思路：首先以氧膦炔(O-C≡P)–为合成模块，制备得到稳定的膦烯酮类化合物(R–P=C=O)；然后研究磷烯酮化合物和NHCs的反应过程；再次系统的研究这些生成的含磷化合物和一些不饱和底物的反应活性，从中筛选出一些可以重新释放出NHCs，并能生成磷杂环的反应类型。这样就可以做到以NHCs为催化剂，以膦烯酮类化合物为模板而制备出一系列磷杂环。最后，本项目还将通过实验结果和理论计算相结合的方法来进一步研这类反应的机理。

N-heterocyclic carbenes (NHCs) have received considerable interested from chemistry ever since the isolation of the first stable NHCs. They have been widely applied in organometallic catalysis、 main-group chemistry、and organocatalysis. Recently, phosphorus chemistry has been advanced dramatically with the help of modern synthetic technology and characterization tools. However, the synthesis of highly reactive phosphorus heterocycles is still limited. Here we propose a new approach for the synthesis of phosphorus heterocycles with the presence of catalytic amount of NHCs: At first, we would prepare some stable phosphaketenes (R-P=C=O) with phosphaethynolate (O-C≡P)– as building block; Secondly, the reaction process between phosphaketenes and NHCs would be studied systematically; Third, the reactivity of these adduct toward unsaturated substances will be investigated systematically, and we are focus on those reactions where NHCs will be released and the phosphorus heterocycles will be prepared. Therefore, with NHCs as catalyst, phosphorus heterocycles can be prepared from phosphaketenes. At last, the reaction mechanisms are going to be studied with the combination of experimental results and density functional theory calculations.