α-Tetrasubstituted Aldehydes through Electronic and Strain-Controlled Branch-Selective Stereoselective Hydroformylation
作者:Josephine Eshon、Floriana Foarta、Clark R. Landis、Jennifer M. Schomaker
DOI:10.1021/acs.joc.8b01431
日期:2018.9.7
high conversions and yields of tetrasubstituted aldehydes (e.g., 13:1 regioselectivity, 85% ee, and <1% hydrogenation for 1-fluoromethyl acrylate). The scope also encompasses both acyclic 1,1′-disubstituted and trisubstituted, electron-poor alkenes as well as di- and trisubstituted alkenes composed of small rings with exocyclic and endocyclic unsaturation. For example, 1-methylene-β-lactam furnished
Unusual methylation reaction of gem-bromofluorospiropentanes with methyllithium
作者:Elena B. Averina、Kseniya N. Sedenkova、Ilya S. Borisov、Yuri K. Grishin、Tamara S. Kuznetsova、Nikolai S. Zefirov
DOI:10.1016/j.tet.2009.05.032
日期:2009.7
A series of novel gem-bromofluorospiropentanes were synthesized and investigated in the reaction with methyllithium. Either substitution of the fluorine atom for a methyl group or rearrangement into methylated cyclobutene derivatives occurred under these conditions.
A copper-catalyzed ring-opening hydroamination of methylenecyclopropanes with polymethylhydrosiloxane and O-benzoylhydroxylamines has been developed. The cyclopropane C–C bond cleavage occurs selectively at the more congested proximal position, and the corresponding homoallylamines are obtained in good to excellent yields. The umpolung electrophilic amination strategy with the hydroxylamine derivatives
Nickel-Catalyzed Ring-Opening Three-Component Coupling of Methylenecyclopropane with Aldehydes and Silanes
作者:Kenichi Ogata、Yuka Atsuumi、Shin-ichi Fukuzawa
DOI:10.1021/ol101838q
日期:2010.10.15
A nickel-catalyzed three-component coupling between methylenecyclopropane, aldehydes, and silanes afforded silylated allylic alcohols that possess an alkyl substituent at the 2-position via cleavage of the proximal C-C bond of methylenecyclopropane