Hypervalent Iodine(III) Reagents as Safe Alternatives to α-Nitro-α-diazocarbonyls
作者:Ryan P. Wurz、André B. Charette
DOI:10.1021/ol034672g
日期:2003.6.1
A cyclopropanation reaction involving iodonium ylides generated in situ allows for efficient preparation of substituted 1-nitro-1-carbonyl cyclopropanes. This robust cyclopropanation reaction can be performed in organic solvents, biphasic aqueous media, or under solvent-free conditions with alkene substrates. The iodonium ylides generated in situ display some surprising differences in reactivity when
Nitrocyclopropanes from nitrodiazomethanes. Preparation and reactivity
作者:P.E. O'Bannon、William P. Dailey
DOI:10.1016/s0040-4020(01)89052-9
日期:——
Nitrodiazo compounds cyclopropanate electron rich alkenes in the presence of rhodium(II) acetate. The yields and diastereoselectivities are dependent on both the alkene and the nitrodiazo precursor. Nitrocyclopropanecarboxylates undergo ring opening, reduction and hydrolysis.
Doubly Activated Cyclopropanes as Synthetic Precursors for the Preparation of 4-Nitro- and 4-Cyano-dihydropyrroles and Pyrroles
作者:Ryan P. Wurz、André B. Charette
DOI:10.1021/ol050442l
日期:2005.6.1
ketones have been prepared in an expedient manner from cyclopropanation reactions of alkenes by diazo compounds or in situ-generated phenyliodonium ylides catalyzed by Rh(II) carboxylates. The doubly activated cyclopropanes were used as synthetic precursors for the regiospecific synthesis of 4-nitro- and 4-cyano-dihydropyrroles upon treatment with primaryamines. Oxidation of the dihydropyrroles with DDQ
The synthesis of nitrocyclopropanes from nitrodiazomethanes
作者:P.E. O'Bannon、William P. Dailey
DOI:10.1016/s0040-4039(01)80688-2
日期:1989.1
The synthesis of novel 1-substituted nitrocyclopropanes using the rhodium(II) acetate catalyzed cyclopropanation reaction of several nitrodiazomethanes with electron rich alkenes is described.
Asymmetric Rh(II)-Catalyzed Cyclopropanation of Alkenes with Diacceptor Diazo Compounds: <i>p</i>-Methoxyphenyl Ketone as a General Stereoselectivity Controlling Group
作者:Vincent N. G. Lindsay、Cyril Nicolas、André B. Charette
DOI:10.1021/ja201237j
日期:2011.6.15
α-PMP-ketone group were found to be effective carbene precursors for the highly stereoselective Rh(2)(S-TCPTTL)(4)-catalyzed cyclopropanation of alkenes (EWG = NO(2), CN, CO(2)Me). The resulting products were readily transformed into a variety of biologically relevant enantiopure molecules, such as cyclopropane α- and β-amino acid derivatives. Different mechanistic studies carried out led to a rationale for the