Music Arif, Hoarau Clément, Hilgert Nicolas, Zischka Florian, Didier Dorian
Department Chemie, Ludwig-Maximilians-Universität, Butenandtstraße 5-13, 81377, Munich, Germany.
Ecole Polytechnique, Route de Saclay, 91128, Palaiseau Cedex, France.
Angew Chem Int Ed Engl. 2019 Jan 21;58(4):1188-1192. doi: 10.1002/anie.201810327. Epub 2018 Dec 17.
Described is the in situ formation of triorganocerium reagents and their application in catalyst-free Zweifel olefinations. These unique cerium species were generated through novel exchange reactions of organohalides with n-Bu Ce reagents. The adequate electronegativity of cerium allowed for compensating the disadvantages of both usually functional-group-sensitive organolithium species and less reactive organomagnesium reagents. Exchange reactions were performed on aryl and alkenyl bromides, enabling enantiospecific transformations of chiral boron pinacol esters. Finally, these new organocerium species were engaged in selective 1,2-additions onto enolisable and sterically hindered ketones.
本文描述了三有机铈试剂的原位形成及其在无催化剂的茨魏费尔烯烃化反应中的应用。这些独特的铈物种是通过有机卤化物与正丁基铈试剂的新型交换反应生成的。铈具有适当的电负性，能够弥补通常对官能团敏感的有机锂物种和反应活性较低的有机镁试剂的缺点。在芳基和烯基溴化物上进行交换反应，实现了手性硼酸频哪醇酯的对映选择性转化。最后，这些新型有机铈物种用于对可烯醇化的位阻酮进行选择性1,2-加成反应。
