A Route to “all-cis” 2-Methyl-6-Substituted Piperidin-3-ol Alkaloids from syn-(2R,1′S)-2-(1-Dibenzylaminomethyl)epoxide: Rapid Total Synthesis of (+)-Deoxocassine
作者:Pierre-Yves Géant、Jean Martínez、Xavier J. Salom-Roig
DOI:10.1002/ejoc.201101333
日期:2012.1
to the synthesis of two cis-2-methyl-6-substituted piperidin-3-ols is described. syn-(2R,1′S)-2-(1-Dibenzylaminomethyl) epoxide (13) was used as common building block. The key step involved oxirane ring opening of 13 by the nucleophilic lithium aza-enolate of hydrazones 12a and 12b. Subsequent hydrazone hydrolysis and intramolecular reductive amination afforded the alkaloid (+)-deoxocassine and a new
MnO<sub>2</sub> as a terminal oxidant in Wacker oxidation of homoallyl alcohols and terminal olefins
作者:Rodney A. Fernandes、Gujjula V. Ramakrishna、Venkati Bethi
DOI:10.1039/d0ob01344g
日期:——
PdCl2/CrO3/HCl produced α,β-unsaturated ketonesfrom homoallyl alcohols, the present method provided orthogonally the β-hydroxy-methyl ketones. No overoxidation or elimination of benzylic and/or β-hydroxy groups was observed. The method could be extended to the oxidation of simple terminalolefins as well, to methyl ketones, displaying its versatility. An application to the regioselective synthesis of gingerol is
Synthesis of 5-Vinyl-2-isoxazolines by Palladium-Catalyzed Intramolecular <i>O</i>-Allylation of Ketoximes
作者:Rodney A. Fernandes、Ashvin J. Gangani、Arpita Panja
DOI:10.1021/acs.orglett.1c01897
日期:2021.8.20
An efficient method for the synthesis of 5-vinyl-2-isoxazolines by Pd-catalyzed intramolecular O-allylation of ketoximes has been developed. The reaction involves Pd(0)-catalyzed π-allyl formation via leaving group ionization or Pd(II)-catalyzed allylic C–H activation followed by intramolecular nucleophilic oxime oxygen attack. This methodology has been elaborated to various value-added products by
Hypervalent Iodine as a Terminal Oxidant in Wacker-Type Oxidation of Terminal Olefins to Methyl Ketones
作者:Dipali A. Chaudhari、Rodney A. Fernandes
DOI:10.1021/acs.joc.6b00137
日期:2016.3.4
the Wacker process for C═O bond formation in terminal olefins can be initiated by a combination of the Pd(II) and hypervalentiodinereagent, Dess–Martin periodinane to generate methyl ketones. This operationally simple and scalable method offers Markovnikov selectivity, has good functional group compatibility, and is mild and high yielding.