The addition of cuprates to vinyltriphenylphosphonium bromide: a synthesis of 1,5-disubstituted Z,Z-penta-1,4-dienes
作者:George Just、Brian O'Connor
DOI:10.1016/s0040-4039(00)94741-5
日期:1985.1
It is shown that alkyl, alkenyl and aryl cuprates add to vinyl- triphenylphosphonium bromide to provide phosphoranes and that the Z:E ratio of their Wittigcondensation products with benzaldehyde and hexanal are strongly influenced by the addition of hexamethyl- phosphoramide. This reaction is applied to the one-pot synthesis of the title compound.
Reactions of Polymer-Supported α-Selenoaldehydes with Grignard Regents. A Facile Solid-Phase Stereoselective Synthesis of (<i>E</i>)-1,2-Disubstituted Ethenes
作者:Shou-Ri Sheng、Xian Huang
DOI:10.1002/jccs.200300125
日期:2003.8
Polymer-supportedα-selenoaldehydes easily obtained by reaction of polymer-supported 4-(phenyl-seleno)morpholine with aldehydes react with Grignard reagents to form polymer-supported (3-hydroxyalkyl selenides, which were treated with thionyl chloride/triethylamine leading to (E)-1,2-disubstitutedethenes in good yields.
Ligand Control of <i>E</i>/<i>Z</i> Selectivity in Nickel-Catalyzed Transfer Hydrogenative Alkyne Semireduction
作者:Edward Richmond、Joseph Moran
DOI:10.1021/acs.joc.5b01047
日期:2015.7.2
A nickel-catalyzed transfer hydrogenative alkynesemireduction protocol that can be applied to both internal and terminal alkynes using formic acid and Zn as the terminal reductants has been developed. In the case of internal alkynes, the (E)- or (Z)-olefin isomer can be accessed selectivelyunder the same reaction conditions by judicious inclusion of a triphos ligand.
Highly Efficient Allyl Cross-Coupling Reactions of Allylindiums with Organic Electrophiles
作者:Kooyeon Lee、Jinsung Lee、Phil Ho Lee
DOI:10.1021/jo026121u
日期:2002.11.1
This paper describes highly efficient allyl cross-coupling reactions of allylindiums with organic electrophiles such as aryl and vinyl triflates, vinyl halides, dibromoolefin, and alkynyl iodide. The reactions were carried out using 4 mol % Pd(PPh3)4 in the presence of 3 equiv of LiCl in DMF at 100 degrees C under a nitrogen atmosphere. Allylindium, generated from the reaction of 1 equiv of indium
The title reaction is found to proceed in the presence of a palladium catalyst and in the absence of any activator. Various functional groups are tolerated to give a diverse range of 1,4-diene and diarylmethane products, which are ubiquitous units of natural products and pharmaceuticals.