A New Protocol for the In Situ Generation of Aromatic, Heteroaromatic, and Unsaturated Diazo Compounds and Its Application in Catalytic and Asymmetric Epoxidation of Carbonyl Compounds. Extensive Studies To Map Out Scope and Limitations, and Rationalization of Diastereo- and Enantioselectivities
作者:Varinder K. Aggarwal、Emma Alonso、Imhyuck Bae、George Hynd、Kevin M. Lydon、Matthew J. Palmer、Mamta Patel、Marina Porcelloni、Jeffery Richardson、Rachel A. Stenson、John R. Studley、Jean-Luc Vasse、Caroline L. Winn
DOI:10.1021/ja034606+
日期:2003.9.1
a general process for the in situ generation of diazo compounds from tosylhydrazone sodium salts has been established and applied in sulfur-ylide mediated epoxidation reactions. The chiral, camphor-derived, [2.2.1] bicyclic sulfide 7 was employed (at 5-20 mol % loading) to render the above processes asymmetric with a range of carbonyl compounds and tosylhydrazone sodium salts. Benzaldehyde tosylhydrazone
已经制备了多种衍生自苯甲醛的金属化甲苯磺酰腙盐,并在四氢噻吩 (THT) (20 mol %) 和 Rh(2)(OAc)(4) (1 mol %) 存在下与苯甲醛反应,得到二氧化二苯乙烯. 在所测试的锂盐、钠盐和钾盐中,发现钠盐的产率和选择性最高。该研究扩展到各种芳香族、杂芳香族、脂肪族、α、β-不饱和和乙炔醛以及酮。总的来说,观察到具有中等至非常高的非对映选择性的环氧化物的高产率。还使用相同的方案在与苯甲醛的反应中检查了衍生自芳香族、杂芳香族和 α,β-不饱和醛的范围广泛的甲苯磺酰腙盐,再次,在大多数情况下观察到良好的产率和高的非对映选择性。因此,已经建立了从甲苯磺酰腙钠盐原位生成重氮化合物的一般方法,并将其应用于硫-叶立德介导的环氧化反应。使用手性、樟脑衍生的 [2.2.1] 双环硫化物 7(以 5-20 mol% 负载量)使上述过程与一系列羰基化合物和甲苯磺酰腙钠盐不对称。苯甲醛甲苯磺酰腙钠盐提供