2-取代的吲哚和苯并呋喃的合成是通过亲核芳族取代,随后在亲核体和邻乙炔之间进行5-endo-dig环化来实现的。乙炔起着吸电子基团的双重作用,以激活S N Ar的底物,而C1-C2碳骨架则用于新形成的5元杂芳族环。这种方法可以使Ar–X–N / O–C1的键形成顺序在一个合成步骤中进行,从而以中等至高收率提供吲哚和苯并呋喃。由于该方法不是过渡金属介导的,因此可以耐受溴化和氯化的底物,可以使用水或水-DMSO混合物作为溶剂进行苯并呋喃的形成。
Highly efficient synthesis of 1,2-disubstituted acetylenes derivatives from the cross-coupling reactions of 1-bromoalkynes with organotitanium reagents
作者:Chuan Wu、Qing-Han Li
DOI:10.1016/j.tet.2021.132370
日期:2021.9
A Highly efficient route for the synthesis of 1,2-disubstituted acetylene derivatives has been developed by nickel catalyzed cross-couplings of alkynyl halides with aryl titanium reagents under mild conditions. This has given corresponding cross-coupling products good to excellent isolated yields of up to 92 %. The aryls bearing electron-donating or electron-withdrawing groups in either alkynylhalides
LiHMDS-Promoted Palladium-Catalyzed Sonogashira Cross-Coupling of Aryl Fluorides with Terminal Alkynes
作者:Jingjing He、Kang Yang、Jianhong Zhao、Song Cao
DOI:10.1021/acs.orglett.9b03815
日期:2019.12.6
A highly efficient Pd-catalyzed Sonogashira coupling of various aryl fluorides with terminalalkynes in the presence of LiHMDS was developed. Both unreactive electron-rich fluoroarenes and electron-poor fluoroarenes proceeded smoothly and afforded the corresponding internalalkynes in moderate to excellent yields.
cross-coupling reaction of arylhalides with a variety of terminal alkynes under amine-free conditions in dimethylformamide (DMF) at 80 °C gave internal arylated alkynes using PdCl2(MeCN)2 with phosphine-free hydrazone 2a as a ligand and CuI as the cocatalyst in good yields. We also found PdCl2/hydrazone ligand 1d in PhMe at 80 °C was a phosphine-free efficient catalyst system for a Hiyama cross-coupling
The Sonogashira coupling reaction of aryl bromides with a variety of terminalalkynes in DMSO at 125 °C gave internal arylated alkynes using low-loaded Pd(acac) 2 with hydrazone as a ligand and CuI as the co-catalyst in good yields.
芳基溴化物与各种末端炔烃在 DMSO 中在 125 °C 下进行 Sonogashira 偶联反应,使用低负载的 Pd(acac) 2 以腙作为配体和 CuI 作为助催化剂以良好的产率得到内部芳基化炔烃。
Copper-catalyzed synthesis of internal alkynesvia domino coupling between 1,1-dihalo-1-alkenes and arylboronic acids
作者:Hong Yan、Linhua Lu、Peng Sun、Yan Zhu、Hailong Yang、Defu Liu、Guangwei Rong、Jincheng Mao
DOI:10.1039/c2ra21577b
日期:——
We have developed the practical copper-catalyzed formation of various internal alkynes via domino couplings between 1,1-dihalo-1-alkenes and arylboronic acids in the presence of low-cost 8-hydroxylquinoline as the ligand.