Microwave Enhanced Glaser Coupling Under Solvent Free Conditions
作者:G. W. Kabalka、L. Wang、R. M. Pagni
DOI:10.1055/s-2001-9726
日期:——
A microwave enhanced, solvent free, Glaser coupling reaction has been developed. Self coupling of terminal alkynes on potassium fluoride-alumina in the presence of cupric chloride affords good yields of the corresponding diacetylenes.
A simple synthesis of unsymmetrical buta-1,3-diynes by cross-coupling of terminalalkynes with 1-bromoalkynes in the presence of copper(I) iodide and tris(o-tolyl)phosphine was developed that gives good yields under simple and mild reaction conditions. The scope and limitations of the cross-coupling reaction were investigated. alkynes - catalysis - cross-coupling - alkadiynes
A method for the Glaser coupling reaction of alkynes by using a vibration ballmill has been developed. The procedure avoids the use of ligands and solvents during the reaction. Aryl‐ and alkyl‐substituted terminalalkynes undergo homocoupling if coground with KF–Al2O3 and CuI as a milling auxiliary and catalyst. Furthermore, an alternative protocol has been developed incorporating 1,4‐diazabicyclo[2
已经开发出一种使用振动球磨机进行炔烃的格拉泽偶联反应的方法。该过程避免了反应期间使用配体和溶剂。如果与作为研磨助剂和催化剂的KF–Al 2 O 3和CuI共同研磨,则芳基和烷基取代的末端炔烃会发生均偶联。此外,还开发了一种替代方案,其中加入了1,4-二氮杂双环[2.2.2]辛烷(DABCO)作为额外的碱,允许使用KF-Al 2 O 3和KF较低的负载。除铜盐外,镍或钴盐以及PdCl 2还催化苯乙炔的均偶联。在通过氟化物引发的三甲基甲硅烷基基团原位脱保护炔烃之后,可以将TMS保护的苯乙炔直接转化为均偶联产物。
Palladium-Catalyzed Cross-Coupling Reactions of 1,2-Diiodoalkenes with Terminal Alkynes: Selective Synthesis of Unsymmetrical Buta-1,3-diynes and 2-Ethynylbenzofurans
for the preparation of unsymmetricalbuta-1,3-diynes and 2-ethynylbenzofurans. In the presence of palladium(II)acetate and copper(I) iodide, unsymmetrical buta-1,3-diynes wereselectively obtained in moderate to good yields. Moreover, 2-ethynylbenzofuranswere obtained in one pot from the reaction of 2-ethynylphenol with( E)-1,2-diiodoalkenes, palladium(II)acetate, and copper(I) iodide by simple heating
Studies on cyclization of o-(alka-1,3-diynyl)arenediazonium salts
作者:O. V. Vinogradova、V. N. Sorokoumov、S. F. Vasilevskii、I. A. Balova
DOI:10.1007/s11172-008-0228-z
日期:2008.8
The Richter reaction of o-(alka-1,3-diynyl)arenediazonium salts, obtained by diazotization of diacetylenic derivatives of anilines, leads to 3-alkynyl-4-chloro- or 3-alkynyl-4-bromocinnolines and/or 3-alkynyl-4-hydroxycinnolines (the latter cyclize into furo[3,2-c]-cinnolines under the reaction conditions). 3-Alkynyl-4-chlorocinnolines undergo solvolysis in methanol giving rise to 3-alkynyl-4-methoxycinnolines