Development of Biisoquinoline-Based Chiral Diaminocarbene Ligands: Enantioselective S<sub>N</sub>2‘ Allylic Alkylation Catalyzed by Copper−Carbene Complexes
作者:Hwimin Seo、Dimitri Hirsch-Weil、Khalil A. Abboud、Sukwon Hong
DOI:10.1021/jo702512z
日期:2008.3.1
Chiral biisoquinoline-based diaminocarbene ligands (BIQ) were designed to create a chiral environment extended toward the metal center, which was confirmed by an X-ray structure. The concise ligand synthesis is highlighted by a modified Bischler−Napieralski cyclization of bisamides prepared from readily available chiral phenethylamines, and allows easy variation of the stereodifferentiating groups
设计基于手性双异喹啉的二氨基碳烯配体(BIQ),以创建向金属中心延伸的手性环境,这通过X射线结构得以证实。简明的配体合成是由易得的手性苯乙胺制备的双酰胺的Bischler-Napieralski环的修饰Bischler-Napieralski环合突出显示的,并且可以轻松改变立体分化基团。环己基-BIQ-铜配合物是使用Grignard试剂进行对映选择性S N 2'烯丙基烷基化的有效催化剂,显示出S N 2'区域选择性高于5:1,对映选择性在68-77%ee范围内。
Direct Synthesis of Thioethers from Carboxylates and Thiols Catalyzed by FeCl<sub>3</sub>
作者:Kunuru Venkatesham、Chitturi Bhujanga Rao、Chanti Babu Dokuburra、Richard A. Bunce、Yenamandra Venkateswarlu
DOI:10.1021/acs.joc.5b02143
日期:2015.11.20
A new and efficient method has been developed for the synthesis of thioethers from carboxylates and thiols. The reaction proceeds via a Fe(III)-catalyzed direct displacement of carboxylates from benzylic or allylic esters by heterocyclic thiols. Short reaction times, good to excellent yields of products, and few side reactions are the significant features of the new protocol.