Reductive Chlorination and Bromination of Ketones via Trityl Hydrazones
作者:Julius R. Reyes、Viresh H. Rawal
DOI:10.1002/anie.201510909
日期:2016.2.24
A method is presented for the direct transformation of a ketone to the corresponding reduced alkyl chloride or bromide. The process involves the reaction of a ketone trityl hydrazone with tBuOCl to give a diazene which readily collapses to the α‐chlorocarbinyl radical, reduction of which by a hydrogen atom source gives the alkyl chloride product. The use of N‐bromosuccinimide provides the corresponding
Cobalt-Catalyzed Ortho Alkylation of Aromatic Imines with Primary and Secondary Alkyl Halides
作者:Ke Gao、Naohiko Yoshikai
DOI:10.1021/ja403759x
日期:2013.6.26
alkylation of aromatic imines with alkyl chlorides and bromides, which allows the introduction of a variety of primary and secondaryalkyl groups at room temperature. The stereochemical outcomes of the reaction of secondaryalkylhalides suggest that the present reaction involves single-electrontransfer from a cobalt species to the alkylhalide to generate the corresponding alkyl radical. A cycloalkylated
Simple, Chemoselective Hydrogenation with Thermodynamic Stereocontrol
作者:Kotaro Iwasaki、Kanny K. Wan、Alberto Oppedisano、Steven W. M. Crossley、Ryan A. Shenvi
DOI:10.1021/ja412342g
日期:2014.1.29
Few methods permit the hydrogenation of alkenes to a thermodynamically favored configuration when steric effects dictate the alternative trajectory of hydrogen delivery. Dissolving metal reduction achieves this control, but with extremely low functional group tolerance. Here we demonstrate a catalytic hydrogenation of alkenes that affords the thermodynamic alkane products with remarkably broad functional group compatibility and rapid reaction rates at standard temperature and pressure.