缩合 d'enolates(例如 l'enolate de Li de la dimethyl-2,6 cyclohexene-2one) avec le trichloroethylene, d'autres ethylenes polyhalogenes et le perchlorobutadiene-1,3。机制。全氯丁烯的内酯化作用。氯乙炔缩合
Synthesis of Bridged Azacycles and Propellanes via Nitrene/Alkyne Cascades
作者:Qinxuan Wang、Jeremy A. May
DOI:10.1021/acs.orglett.0c00798
日期:2020.4.17
nitrene tether showed that 7-membered rings were the maximum ring size to be formed by nitrene attack on the alkyne. Examples incorporating stereocenters on the carbonazidate’s tether induced diasteroselectivity in the formation of the bridgedring and two new stereocenters. Additionally, propellanes containing aminals, hemiaminals, and thioaminals formed from the bridged azacycles in the same reaction via
Chloroacetylenes as Michael acceptors. II. Direct ethynylation and vinylation of tertiary enolates.
作者:Andrew S. Kende、Pawel Fludzinski
DOI:10.1016/s0040-4039(00)87345-1
日期:1982.1
The reaction of ClCCCl, PhCCCl and PhSCCCl with a variety of tertiaryenolates leads in 43–90% yields to α-chloroethynyl, α-phenylethynyl and α-thiophenylethynyl derivatives. The −CCCl group is smoothly converted to −CCH using copper powder in HOAc/THF, or is directly reduced (H2/Lindlar catalyst) to the −CHCH2 group, thus providing facile access to many α-ethynyl and α-vinyl ketones and esters
Rh(II)-Catalyzed Chemoselective Oxidative Amination and Cyclization Cascade of 1-(Arylethynyl)cycloalkyl)methyl Sulfamates
作者:Dong Pan、Yin Wei、Min Shi
DOI:10.1021/acs.orglett.7b01558
日期:2017.7.7
A Rh(II)-catalyzed chemoselective oxidative amination and cyclization cascade of 1-(arylethynyl)cycloalkyl)methyl sulfamates has been presented. For a cyclopropyl or cyclobutyl moiety containing alkynyl sulfamates, the reactions underwent a metallonitrene-initiated alkyne oxidation along with cyclopropyl ring expansion or alkoxyl moiety migration to give cyclobutane-fused or methylenecyclobutane-containing
Synthesis of 2(3<i>H</i>)-Furanones via Electrophilic Cyclization
作者:Ziwei W. Just、Richard C. Larock
DOI:10.1021/jo702666j
日期:2008.4.1
variety of highly substituted 2(3H)-furanones are readily prepared from 3-alkynoate esters and the corresponding acids via electrophilic cyclization. Successful electrophiles in this process include I2, ICl, and PhSeCl. This highly efficient process proceeds under mild conditions, tolerates various functional groups, and generally provides substituted 2(3H)-furanones in good to excellent yields.
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‐Directing‐Group Strategy Unlocks Enantioselective (3+1+2) Carbonylative Cycloadditions of Aminocyclopropanes
作者:Olga O. Sokolova、John F. Bower
DOI:10.1002/anie.202205007
日期:2022.8.8
An endo-directing group strategy enables enantioselective (3+1+2) cycloadditions that are triggered by carbonylative C−C bond activation of cyclopropanes. These processes are rare examples of cycloadditions where C−C bond oxidative addition is enantiodetermining.