Organocatalytic Asymmetric Bromination of Alkenes

单对映体的化学制备在药物化学、精细化工和学术领域具有重要意义。手性催化剂的使用被广泛认为是诱导不对称的最有效的方法。目前已有几种极好的催化不对称合成eg环氧化物的方法，这些方法为制备其他对映物材料提供了基础。迄今为止，烯烃的催化不对称溴化尚未实现。考虑到溴化是一个经典的教科书反应，以及通过广泛的亲核试剂的立体特异性亲核置换获得的对映体纯溴的潜在效用，这有点令人惊讶。在此，我们建议发展一种烯烃的一般催化不对称溴化反应。催化剂将基于2,6-二取代碘苯，其中事实上的催化实体将具有高价X-I-Br键。催化剂将被设计成亲电溴是一个高度不对称的区域。

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.