Department of Chemistry, University of California, Irvine, California 92697-2025, USA.
J Am Chem Soc. 2013 Jun 19;135(24):9083-90. doi: 10.1021/ja4034999. Epub 2013 Jun 10.
The first Negishi nickel-catalyzed stereospecific cross-coupling reaction of secondary benzylic esters is reported. A series of traceless directing groups is evaluated for ability to promote cross-coupling with dimethylzinc. Esters with a chelating thioether derived from commercially available 2-(methylthio)acetic acid are most effective. The products are formed in high yield and with excellent stereospecificity. A variety of functional groups are tolerated in the reaction including alkenes, alkynes, esters, amines, imides, and O-, S-, and N-heterocycles. The utility of this transformation is highlighted in the enantioselective synthesis of a retinoic acid receptor agonist and a fatty acid amide hydrolase inhibitor.
首次报道了首例尼希基镍催化的立体特异性仲苄基酯交叉偶联反应。评估了一系列无痕迹导向基团促进与二甲基锌交叉偶联的能力。具有来源于市售 2-(甲硫基)乙酸的螯合硫醚的酯是最有效的。产物以高产率和优异的立体选择性形成。反应中包括烯烃、炔烃、酯、胺、酰亚胺以及 O、S 和 N 杂环在内的各种官能团都能被容忍。该转化的实用性在视黄酸受体激动剂和脂肪酸酰胺水解酶抑制剂的对映选择性合成中得到了强调。