1,2-Bis(diphenylphosphino)carborane As a Dual Mode Ligand for Both the Sonogashira Coupling and Hydride-Transfer Steps in Palladium-Catalyzed One-Pot Synthesis of Allenes from Aryl Iodides
作者:Hiroyuki Nakamura、Takaya Kamakura、Shinya Onagi
DOI:10.1021/ol060538v
日期:2006.5.1
One-pot allene synthesis from aryl iodides 1 and propargyldicyclohexylamine 2 proceeded in the presence of Pd(2)(dba)(3).CHCl(3) catalyst (2.5 mol %), 1,2-bis(diphenylphosphino)carborane 5 (10 mol %), CuI (15 mol %), and Et(3)N (150 mol %) to give the corresponding allenes 4 in good to high yields. Electron-deficient bidentate phosphines, such as 1,2-bis(diphenylphosphino)carborane 5 and (C(6)F(5))
Mono- and 1,3-disubstituted allenes were synthesized from the corresponding propargylamines via palladium-catalysed hydride-transferreaction. In the current transformation, propargylic amines can be handled as allenyl anion equivalents and introduced into various electrophiles to be transformed into allenes under palladium-catalyzed conditions.
The palladium-catalyzed allene transformation reaction from propargylic amines proceeded in the presence of Pd2(dba)3·CHCl3 (5 mol %) and (C6F5)2PC2H4P(C6F5)2 (10 mol %) in CHCl3 at room temperature to give the corresponding allenes in good to high yields. Dicyclohexyl groups substituted on the nitrogen of propargylic amines were found to be effective for the current transformation and the conjugated
在Pd 2(dba)3 ·CHCl 3(5 mol%)和(C 6 F 5)2 PC 2 H 4 P(C 6 F 5)2(Pd 2(dba)3在室温下,将其在CHCl 3中的10mol%)以高至高收率得到相应的烯丙基。发现在炔丙基胺的氮上取代的二环己基可有效地进行电流转化,并由相应的炔丙基胺3合成了共轭烯-丙二烯4 在温和的条件下。
Synthesis of Terminal Allenes through Copper-Mediated Cross-Coupling of Ethyne with<i>N</i>-Tosylhydrazones or α-Diazoesters
作者:Fei Ye、Chengpeng Wang、Xiaoshen Ma、Mohammad Lokman Hossain、Ying Xia、Yan Zhang、Jianbo Wang
DOI:10.1021/jo502316q
日期:2015.1.2
Ethyne is employed as coupling partner in copper-mediated cross-coupling reactions with N-tosylhydrazones and alpha-diazoacetate, leading to the development of a new synthetic method for terminal allenes. With this novel coupling method, the terminal allenes were obtained in good yields and with excellent functional group tolerance. Copper carbene migratory insertion is proposed as the key step in these transformations.