Highly general stereo-, regio-, and chemo-selective synthesis of terminal and internal conjugated enynes by the Pd-catalysed reaction of alkynylzinc reagents with alkenyl halides
作者:Anthony O. King、Nobuhisa Okukado、Ei-ichi Negishi
DOI:10.1039/c39770000683
日期:——
The reaction of an alkynylzinc chloride, readily obtainable from the corresponding alkynyl-lithium and anhydrous zinc chloride, with an alkenyl iodide or bromide in the presence of a catalytic amount of a Pd–phosphine complex provides the corresponding terminal or internal enyne in high yield, the stereospecificity of the reaction being 97%.
Pd‐Catalyzed Tandem Pathway for Stereoselective Synthesis of (<i>E</i>)‐1,3‐Enyne from <i>β</i>‐Nitroalkenes by Using a Sacrificial Directing Group
作者:Subal Mondal、Siba P. Midya、Suman Das、Soumya Mondal、Abu S. M. Islam、Pradyut Ghosh
DOI:10.1002/chem.202301637
日期:2023.11.2
Dancing hybridization: The first example of efficient and stereoselective (E)-1,3-enyne synthesis exclusively from alkene substrates is described. Inauguration of nitro group as a sacrificial directing group, formation of magical triple bond by promoting zero-order to third-order upgradation make this methodology atom and step efficient with sustainability.
跳舞杂交:描述了仅从烯烃底物有效且立体选择性 ( E )-1,3-烯炔合成的第一个例子。硝基作为牺牲导向基团的诞生,通过促进零级到三级升级形成神奇的三键,使该方法原子和步骤高效且可持续。
Synthesis of (Z)-tributylstannyl enynes: systematic studies of Sonogashira cross-coupling reactions between (E)-1-iodovinyl-1-tributylstannanes and terminal acetylenes using amines or tetrabutylammonium hydroxide (TBAOH) as activator
作者:Carlos E.D. Nazario、Amanda S. Santana、Cristiane Y. Kawasoko、Carlos A. Carollo、Gabriela R. Hurtado、Luiz H. Viana、Sandro L. Barbosa、Palimécio G. Guerrero、Francisco A. Marques、Vânia B. Dabdoub、Miguel J. Dabdoub、Adriano C.M. Baroni
DOI:10.1016/j.tetlet.2011.06.004
日期:2011.8
Sonogashira cross-coupling reactions involving (E)-iodo vinyl stannanes and terminal acetylenes were carried out in the presence of Pd(PPh(3))(4), Cul and several amines, affording (Z)-tributylstannyl enynes in moderate to good yields (62-91%). Utilizing the catalytic system containing Pd(PPh(3))(4) (5%), Cul (10%), and TBAOH (40% in aqueous media) as activator, better yields (72-91%) and lower reaction times were achieved. (C) 2011 Elsevier Ltd. All rights reserved.
Versatile palladium(II)-catalyzed Negishi coupling reactions with functionalized conjugated alkenyl chlorides
Under palladium catalysis, we found that organozincate reagents, generated in situ, by reaction of Grignard compounds with less than molar amounts of zinc chloride, in the presence of conjugated alkenyl chlorides, give rapidly and cleanly the corresponding coupling product in high yields. In this way, aryl as well as primary and secondary alkyl substituents have been introduced successfully. The selectivity of the reaction allows to prepare various functionalized conjugated enynes and dienes from chloroenyne and chlorodiene derivatives bearing a functional group. (C) 2003 Elsevier Ltd. All rights reserved.