过渡金属催化的对映选择性氮宾转移到硫化物已成为快速构建对映体富集的硫酰亚胺的最有力的策略之一。然而,与贵金属相比,实现对地球丰富的高活性过渡金属氮烯中间体的立体控制仍然是一个艰巨的挑战。在此,我们公开了使用亚氨基碘烷作为氮宾前体的手性铁(II)/ N , N'-二氧化物催化的二烷基硫醚和烷基芳基硫醚的对映选择性酰亚胺化。以中等至良好的收率和高对映选择性获得了一系列手性磺酰亚胺(56 个实例,收率高达 99%,98:2 er)。通过复杂分子的后期修饰以及手性杀虫剂氟啶虫胺和相关生物活性化合物中间体的合成,证明了该方法的实用性。基于实验研究和理论计算,水键合的高自旋铁氮化物被确定为关键中间体。观察到的立体选择性源于手性洞穴中配体的酰胺单元与硫化物的大取代基之间的空间排斥。此外,二恶唑酮被证明是在铁(III)/ N , N'-二氧化物络合物存在下合适的酰基氮烯前体,导致形成对映选择性反转的硫酰亚
Enantioselective Nitrene Transfer to Sulfides Catalyzed by a Chiral Iron Complex
作者:Jun Wang、Marcus Frings、Carsten Bolm
DOI:10.1002/anie.201304451
日期:2013.8.12
Iron works: Enantioselectivenitrenetransfer to sulfide was accomplished by a chiraliron(III)/PyBOX catalyst (see scheme). Various sulfimides were thus obtained in high enantioselectivities and yields. Applications of this protocol to the syntheses of enantioenriched sulfoximines and an epoxide were also demonstrated.
An (OC)Ru(II)(salen) complex was found to catalyze imidation of alkyl aryl sulfides in the presence of azide with high enantioselectivity as well as good chemical yield. (C) 2001 Elsevier Science Ltd. All rights reserved.
Catalytic Asymmetric Sulfimidation
作者:Hiroya Takada、Yoshiaki Nishibayashi、Kouichi Ohe、Sakae Uemura、Charlotte P. Baird、Tim J. Sparey、Paul C. Taylor
DOI:10.1021/jo970798d
日期:1997.9.1
A direct catalytic imidation of sulfides to sulfimides with [N-(p-tolylsulfonyl)imino]phenyliodinane (TsN=IPh) using a catalytic amount of copper triflate (CuOTf) has been developed. The reaction proceeds with a wide range of sulfides to give the corresponding sulfimides in 50-83% isolated yields. When the reaction is applied to allylic sulfides, the products are the corresponding sulfonamides produced via [2,3] sigmatropic rearrangement of the initially formed allylic sulfimides. In the presence of a chiral bis(oxazoline) as ligand, asymmetric induction occurs to afford the chiral sulfimides (up to 71% ee) and sulfonamides (up to 58% ee). Chloramine T (TsNClNa) can be used in place of TsN=IPh for asymmetric sulfimidation, but the ee's are much lower. Some mechanistic observations are described.