Organocatalytic Asymmetric Bromination of Alkenes

单一对映体化合物的制备在药物化学、精细化学品和学术界具有重要意义。使用手性催化剂来实现这一点被广泛认为是诱导不对称性的最有效方式。环氧化物的催化不对称合成已经有了一些很好的方法，这些方法也是制备其他对映体纯物质的基础，但烯烃的催化不对称溴化反应至今尚未实现。这是有点令人惊讶的，因为溴化反应是一个经典的教科书反应，和潜在的实用性所获得的对映体纯的溴化物立体定向亲核取代与广泛的亲核试剂。我们建议在此开发一个通用的催化烯烃的不对称溴化反应。催化剂将基于2，6-二取代的碘代苯，其中事实上的催化实体将具有超价X-I-Br键。催化剂将被设计成使得亲电溴是高度不对称的区域。

The preparation of chemicals as single enantiomers is of vital importance in the fields of pharmaceutical chemistry, fine chemicals and academia. The use of a chiral catalyst in order to do so is widely recognised as the most efficient way of inducing asymmetry. Several excellent methods exist for catalytic asymmetric synthesis of eg epoxides, and these act as building blocks for the preparation of other enantiopure materials.To date the catalytic asymmetric bromination of alkenes has not been achieved. This is somewhat surprising given that bromination is a classic textbook reaction, and the potential utility of the obtained enantiomerically pure bromides by stereospecific nucleophilic displacement with a wide-range of nucleophiles.We propose herein to develop a general catalytic asymmetric bromination reaction of alkenes. The catalysts will be based on 2,6-disubstituted iodobenzenes where the de facto catalytic entity will have a hypervalent X-I-Br bond. The catalysts will be designed so that the electrophilic bromine is a region of high asymmetry.