Synthetic studies on novel catalysts incorporating multi planar-chiral units

本项目旨在开发新的高效合成方法，以提供新的平面手性分子和设计/合成多平面手性分子作为新型相转移催化剂。我们已经完成了一种新的钐介导的分子内pinacol偶联，用于合成一系列环番二醇，收率高达64%，转化为平面手性[n]副环番（8-12）。我们还利用结晶诱导的不对称转变开发了平面手性[11]副环环烷的立体控制。通过（乙烯基）磷烷中间体的反应，合成了一系列[n]副吡啶烷。将这些平面手性吡啶和环烷分子转化为多平面手性铵盐，并在不对称相转移催化下研究了它们的不对称烷基化反应。观察到适度的对映体选择性，高达75%的ee对苯化的甘氨酸衍生物。我们对吡啶烷和环烷催化剂的催化活性进行了全面的研究，前者对不对称烷基化反应表现出较好的对映选择性。

This project aimed the new development of efficient synthetic methodologies to provide novel planar-chiral molecules and design/synthesis of multi planar-chiral molecules as novel phase transfer catalysts.We have accomplished novel samarium-mediated intramolecular pinacol coupling for synthesis of a series of cyclophanediols in up to 64% yield which were transformed to planar-chiral[n] paracyclophanes(8-12). We have also developed stereocontrol of planar-chiral[11] paracyclophanes by using crystallization-induced asymmetric transformation. Synthesis of a series of[n] parapyridinophanes was also developed by the reaction of(vinylimino) phosphorane intermediates.These planar-chiral pyridinophane and cyclophane molecules were transformed to multi planar-chiral ammonium salts and their asymmetric alkylation reactions were investigated as asymmetric phase transfer catalysis. Moderate enantioselectivity was observed with up to 75% ee for benzylation of a glycin derivative. We have thoroughly examined the catalytic activities of the pyridinophane and the cyclophane catalysts and the former showed the better enantioselectivities for asymmetric alkylation reactions.