directing group in C–H bond-functionalization reactions, reductive removal of this directing group is not straightforward. Currently available methods are limited to nickel-catalyzed reactions using i PrMgX or hydrosilane as a reductant, leaving the functional group compatibility issue to be solved. Herein, we report rhodium-catalyzed reductivecleavage of aryl carbamates using i PrOH as a milder reductant
尽管在 C-H 键官能化反应中广泛使用氨基甲酸酯作为导向基团,但还原去除该导向基团并不简单。目前可用的方法仅限于使用 i PrMgX 或氢硅烷作为还原剂的镍催化反应,留下官能团兼容性问题有待解决。在此,我们报告了使用 i PrOH 作为更温和的还原剂对氨基甲酸芳基酯进行铑催化的还原裂解。
Development and Mechanistic Studies of Iron-Catalyzed Construction of Csp<sup>2</sup>–B Bonds via C–O Bond Activation
Herein we describe an iron-catalyzed borylation of alkenyl and arylcarbamatesthrough the activation of a C–O bond. This protocol exhibits high efficiency, a broad substrate scope, and the late-stage borylation of biorelevant compounds, thus providing potential applications in medicinal chemistry. Moreover, this method enables orthogonal transformations of phenol derivatives and also offers good opportunities
在本文中,我们描述了通过C-O键的活化,铁催化的烯基和芳基氨基甲酸酯的硼酸酯化反应。该方案显示出高效率,广泛的底物范围以及生物相关化合物的后期硼化,因此在药物化学中提供了潜在的应用。而且,该方法能够使酚衍生物进行正交转化,并且还为合成多取代的芳烃提供了良好的机会。初步的机理研究表明,通过自由基途径的Fe II / Fe III催化循环可能与反应有关。
Nickel-Catalyzed Amination of Aryl Sulfamates and Carbamates Using an Air-Stable Precatalyst
作者:Liana Hie、Stephen D. Ramgren、Tehetena Mesganaw、Neil K. Garg
DOI:10.1021/ol301847m
日期:2012.8.17
A facile nickel-catalyzed method to achieve the amination of synthetically useful arylsulfamates and carbamates is reported. Contrary to most Ni-catalyzed amination reactions, this user-friendly approach relies on an air-stable Ni(II) precatalyst, which, when employed with a mild reducing agent, efficiently delivers aminated products in good to excellent yields. The scope of the method is broad with
报道了一种简便的镍催化方法来实现合成有用的氨基磺酸芳基酯和氨基甲酸酯的胺化。与大多数 Ni 催化的胺化反应相反,这种用户友好的方法依赖于空气稳定的 Ni(II) 预催化剂,当它与温和的还原剂一起使用时,可以有效地以良好到优异的产率提供胺化产物。该方法的范围就两个偶联伙伴而言都是广泛的,并且包括杂环底物。
Directed <i>ortho</i> Metalation-Based Methodology. Halo-, Nitroso-, and Boro-Induced <i>ipso-</i>Desilylation. Link to an <i>in situ</i> Suzuki Reaction
作者:Zhongdong Zhao、Victor Snieckus
DOI:10.1021/ol0506563
日期:2005.6.1
[reaction: see text] Treatment of DoM-derived silylated aromatics 2-4 under standard electrophilic halogenation conditions cleanly affords ipso-desilyation products 5-7, while nitration of methoxy-substituted analogues 8, 9 leads to non-ipso isomers 10, 12 and 11, 13, controlled by a silicon steric effect. Sequential ipso-borodesilylation of 2a, 3a, and 20 followed by treatment with aryl halides under
was established to be a crucial parameter for this transformation. When combined with DoM and traditional Pd-catalyzed Suzuki-Miyaura strategies, the methodology offers concise routes to uniquely substituted molecules, avoiding the need for protection/deprotection of the phenol and the use of strongly nucleophilic cross-coupling partners.