Alkene Ozonolysis in the Presence of Diazo Functionality: Accessing an Intermediate for Squalestatin Synthesis
作者:Hasanain A. A. Almohseni、Younes Fegheh-Hassanpour、Tanzeel Arif、David M. Hodgson
DOI:10.1055/s-0039-1690180
日期:2019.11
cycloaddition between diazo and alkene functionality, and the tolerance of α-substituted α-diazoesters towards ozone in the presence of an alkene, led to chemoselective alkeneozonolysis of an ε-unsaturated-α-diazoester to give a key racemic diazoketone for the synthesis of 6,7-dideoxysqualestatin H5. Studies on both the propensity for intramolecular cycloaddition between diazo and alkene functionality, and the
Homologation of Electron-Rich Benzyl Bromide Derivatives via Diazo C–C Bond Insertion
作者:Atanu Modak、Juan V. Alegre-Requena、Louis de Lescure、Kathryn J. Rynders、Robert S. Paton、Nicholas J. Race
DOI:10.1021/jacs.1c11503
日期:2022.1.12
The ability to manipulate C–C bonds for selective chemical transformations is challenging and represents a growing area of research. Here, we report a formal insertion of diazo compounds into the “unactivated” C–C bond of benzyl bromide derivativescatalyzed by a simple Lewisacid. The homologation reaction proceeds via the intermediacy of a phenonium ion, and the products contain benzylic quaternary
Synthesis of spiro[2,3-dihydrofuran-3,3′-oxindole] derivatives <i>via</i> a multi-component cascade reaction of α-diazo esters, water, isatins and malononitrile/ethyl cyanoacetate
作者:Taoda Shi、Shenghan Teng、Yajie Wei、Xin Guo、Wenhao Hu
DOI:10.1039/c9gc01751h
日期:——
We report a green synthesis of spiro[2,3-dihydrofuran-3,3′-oxindole] derivatives which are of potential value in medicinal chemistry. We are able to access spiro[2,3-dihydrofuran-3,3′-oxindole] derivatives via a Cu(OTf)2-catalyzed or Cu(OTf)2/Rh2(OAc)4-cocatalyzed multi-component cascade reaction of α-diazo esters, water, isatins and malononitrile/ethyl cyanoacetate. The reaction can be accomplished
A new bismuth(V) oxidative catalytic system has been developed and applied for the conversion of hydrazones into diazo compounds. With the use of low catalytic amounts of Ph3Bi and AcOH with NaBO3·H2O as a terminal oxidant, the in situ formation of Ph3Bi(OAc)2 is capable of oxidizing hydrazones in excellent yields. The reaction was applied for the synthesis of diazocarbonyls and 2,2,2-trifluoromethyl
开发了一种新的铋(V)氧化催化体系,并将其用于将腙转化为重氮化合物。使用低催化量的Ph 3 Bi 和AcOH,NaBO 3 ·H 2 O 作为末端氧化剂, Ph 3 Bi(OAc) 2的原位形成能够以优异的收率氧化腙。该反应用于合成重氮羰基化合物和 2,2,2-三氟甲基重氮烷烃,收率良好。