Palladium-Catalyzed [5 + 2] Annulation of Vinylethylene Carbonates with Barbiturate-Derived Alkenes
摘要:
A palladium/XantPhos-catalyzed [5 + 2] annulation of VECs with electron-deficient alkenes having an isolated carbon-carbon double bond has been developed to afford spirobarbiturate-tetrahydrooxepines. This study provides an expedient assembly of biologically interesting spirobarbiturate-tetrahydrooxepines. The easy scalability and versatile transformability of the reaction products were also exhibited.
C−O coupling of Malonyl Peroxides with Enol Ethers
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[5+2] Cycloaddition: Non‐Rubottom Oxidation
作者:Vera A. Vil'、Evgenii S. Gorlov、Oleg V. Bityukov、Yana A. Barsegyan、Yulia E. Romanova、Valentina M. Merkulova、Alexander O. Terent'ev
DOI:10.1002/adsc.201900271
日期:2019.7.2
Malonyl peroxides act both as oxidants and reagents for C−O coupling in reactions with methyl and silyl enol ethers. In the proposed conditions, the oxidative C−O coupling of malonyl peroxides with enol ethers selectively proceeds, bypassing the traditional Rubottom hydroxylation of enol ethers by peroxides. It was observed that the oxidative [5+2] cycloaddition of malonyl peroxides and enol ethers
FLP-Catalyzed Transfer Hydrogenation of Silyl Enol Ethers
作者:Imtiaz Khan、Benjamin G. Reed-Berendt、Rebecca L. Melen、Louis C. Morrill
DOI:10.1002/anie.201808800
日期:2018.9.17
Herein we report the first catalytic transfer hydrogenation of silylenolethers. This metal free approach employs tris(pentafluorophenyl)borane and 2,2,6,6‐tetramethylpiperidine (TMP) as a commercially available FLP catalyst system and naturally occurring γ‐terpinene as a dihydrogen surrogate. A variety of silylenolethers undergo efficient hydrogenation, with the reduced products isolated in excellent
Divergent Iron-Catalyzed Coupling of<i>O</i>-Acyloximes with Silyl Enol Ethers
作者:Hai-Bin Yang、Nicklas Selander
DOI:10.1002/chem.201605636
日期:2017.2.3
An iron‐catalyzedcoupling reaction of O‐acyloximes and O‐benzoyl amidoximes with silyl enol ethers is reported. The protocol provides access to functionalized pyrroles, 1,6‐ketonitriles, pyrrolines and imidazolines via carbon‐centered radicals generated from an initially formed iminyl radical. The intramolecular cyclization and ring‐opening processes of the iminyl radical take place preferentially
作者:Mikhail D. Kosobokov、Vitalij V. Levin、Marina I. Struchkova、Alexander D. Dilman
DOI:10.1021/acs.orglett.5b00097
日期:2015.2.6
CF2 fragment is described. The reaction involves silylation, room-temperature difluorocyclopropanation of silyl enol ethers, and selective ringopening of cyclopropanes under acidic conditions. The whole three-step sequence is conveniently performed in a one-pot mode.
<i>C</i><sub>1</sub>-Symmetric Oxazolinyl Sulfoximines as Ligands in Copper-Catalyzed Asymmetric Mukaiyama Aldol Reactions
作者:Jörg Sedelmeier、Tim Hammerer、Carsten Bolm
DOI:10.1021/ol703065x
日期:2008.3.1
Aryl-bridged C1-symmetric oxazolinyl sulfoximines are applicable in copper-catalyzedasymmetricMukaiyamaaldolreactions with methyl pyruvate. The resulting alpha-hydroxy esters have been obtained with up to 94% ee in good yields. They contain a quaternary stereogenic center and represent valuable precursors for biologically active molecules.