Asymmetric Synthesis of Cyclic Boronic Esters using Lithiation-Borylation

环丁烷具有刚性的结构，其取代基具有明确的空间排列，并产生不同的生物活性。本项目的目的是开发一种高效的不对称合成具有高度通用的硼酸酯取代基的环丁烷的方法。该合成将通过由高烯丙醇衍生的硼酸酯的锂化-硼化形成的5元环硼酸酯络合物的环收缩进行。对映体纯的高烯丙基醇的容易获得性和用于增加环尺寸和在环形成之前安装额外手性的同系化的潜力使得这种方法特别有吸引力。

Cyclobutanes have a structural rigidity which provides a well-defined spatial arrangement of their substituents and gives rise to diverse bioactivities.The aim of the project is to develop an efficient asymmetric synthesis of cyclobutanes with a highly versatile boronic ester substituent. The synthesis will proceed via the ring contraction of a 5-membered ring boronate complex formed by lithiation-borylation of a homoallylic alcohol derived boronic ester. The easy accessibility of enantiopure homoallylic alcohols and the potential of homologation to be used for increasing ring size and installing additional chirality before ring formation makes this method particularly attractive.The use of this method for the medicinally relevant materials will also be investigated in collaboration with Bayer.