Direct Carboxylation of the Diazo Group <i>ipso</i>-C(sp<sup>2</sup>)–H bond with Carbon Dioxide: Access to Unsymmetrical Diazomalonates and Derivatives
作者:Qianyi Liu、Man Li、Rui Xiong、Fanyang Mo
DOI:10.1021/acs.orglett.7b03573
日期:2017.12.15
The directcarboxylation of the ipso-C(sp2)–H bond of a diazo compound with carbondioxide under mild reaction conditions is described. This method is transition-metal-free, uses a weak base, and proceeds at ambient temperature under atmospheric pressure in carbondioxide. The carboxylation exhibits high reactivity and is amenable to subsequent diversification. A series of unsymmetrical 1,3-diester/keto/amide
Addition of Diazo Compounds <i>ipso</i>-C–H Bond to Carbon Disulfide: Synthesis of 1,2,3-Thiadiazoles under Mild Conditions
作者:Lei Zhang、Beiqi Sun、Qianyi Liu、Fanyang Mo
DOI:10.1021/acs.joc.8b00383
日期:2018.4.6
We describe here an operationally simple and straightforward synthesis method for a series of diverse 4,5-disubstituted 1,2,3-thiadiazoles via the nucleophilic addition of α-diazo carbonyl compounds to carbon disulfide. This method features using abundant and inexpensive carbon disulfide undermild reaction conditions.
Blue light-promoted cross-coupling of aryldiazoacetates and diazocarbonyl compounds
作者:Tiebo Xiao、Mingjing Mei、Yuwei He、Lei Zhou
DOI:10.1039/c8cc04609c
日期:——
distinct diazo compounds was described. The reaction produces E-configured trisubstituted alkenes in good yields in the absence of catalysts and additives. The reactive free carbeneintermediates were generated via selective photolysis of one of the two diazo compounds upon blue light irradiation.
Stability of diazocarbonyl compounds under the conditions of gas chromatography and chromatography-mass spectrometry analysis
作者:T. A. Kornilova、A. I. Ukolov、R. R. Kostikov、I. G. Zenkevich
DOI:10.1134/s1070363212100088
日期:2012.10
The gas chromatographic analysis of alkyldiazoacetates N2CHCO2R (R = CH3 - C4H9), alpha-aliphatic diazoketones RCOCHN2 (R = C3H7, C5H11, and C9H19), and aryl-substituted diazoketones Ph (CH2) (n) COCHN2 (n = 0-2) is shown to be possible when their retention temperatures are below the boiling points of compounds of this series at atmospheric pressure without decomposition (about 140A degrees C). At higher temperatures occurs partial or complete decomposition of alpha-diazoketones in chromatographic columns to form ketenes. Among the impurities in the reaction mixtures at the diazotization of corresponding alkyl glycinates were identified for the first time the nitrate esters of glycolic acid O2NOCH2CO2R, as well as the dimeric products. All diazocarbonyl compounds and the impurities were characterized by mass spectra. For the first time their gas chromatographic retention indices were determined.
Metal-Free Visible-Light Induced Cross-Dehydrogenative Coupling of Tertiary Amines with Diazo Compounds
The first visible-light induced cross-dehydrogenative coupling between tertiary amines and diazo compounds is described. The reaction proceeds smoothly under mild and metal-free conditions by using air or O-2 as the oxidant, affording various beta-amino-alpha-diazo adducts in moderate to good yields with broad substrate scopes. The resulting products were successfully employed for the synthesis of 4- or 5-ester N-aryl-2,3-dihydrobenzo[d]azepines with high regioselectivity simply switched by the selection of the transition metal catalysts.