手性磷酰胺类配体不对称催化串联反应合成手性3-取代苯酞化合物

以反式-1,2-二苯基乙二胺为原料合成了一系列磷酰胺类配体, 考察了该类配体在催化1,2-加成/内酯化串联反应合成手性3-取代苯酞化合物过程中的催化活性. 在最优条件下, 即在配体7d摩尔分数为20%时, 可以获得高达90%的收率及大于80% e.e.值的3-取代苯酞化合物; 该配体合成简单, 虽然作为催化剂使用量较大但较易回收再利用. 对反应机理进行了推测, 认为反应过程中形成的环状过渡态有助于提高反应的对映选择性.

Synthesis of Chiral 3-Substituted Benzoquinone Compounds Through Asymmetric Catalytic Tandem Reaction with Chiral Phosphoramide as Catalyst †

We used thiophosphoramide as a catalyst, which was synthesized after several simple reactions of trans-1,2-diphenyl-ethylenediamine, aromatic aldehydes and arylalkyl zincs or diethylzinc as reactants, to synthesize chiral 3-substituted benzoquinone compounds with important biological activity, through 1,2-addition/lactoneization tandem reaction. The raw materials are cheap and easy to obtain, the catalytic efficiency is high. The yield and e.e. value can be guaranteed to be as high as 80% simultaneously. Despite the large amount of catalyst, the ligand is very convenient to recycle and reuse in this system. At the same time, we speculate on the reaction mechanism, and believe that the quaternary transition state and the six-element transition state formed by the reaction process are beneficial to improve the enantioselectivity of the reaction.