Substrate Control in the Gold(I)-Catalyzed Cyclization of β<i>-</i>Propargylamino Acrylic Esters and Further Transformations of the Resultant Dihydropyridines
作者:Jiří Mikušek、Petr Matouš、Eliška Matoušová、Martin Janoušek、Jiří Kuneš、Milan Pour
DOI:10.1002/adsc.201600412
日期:2016.9.15
β‐propargylamino acrylic esters with a push‐pull olefinic bond afforded good to high yields of dihydropyridines upon treatment with 5% tris(2‐furyl)phosphine‐gold(I) chloride/silver(I) tetrafluoroborate [(TFP)AuCl/AgBF4] in anhydrous benzene. Carbamate and sulfonyl groups were employed for nitrogen protection. On a model enyne, the p‐methoxybenzenesulfonyl (MBS) group was found to be a better protective
Molecular diversity of triphenylphosphine promoted reaction of electron-deficient alkynes and arylidene Meldrum acid (N,N'-dimethylbarbituric acid)
作者:Ying Han、Hui Zheng、Yuan-Yuan Zhang、Chao-Guo Yan
DOI:10.1016/j.cclet.2019.10.042
日期:2020.5
Abstract The three-component reaction of triphenylphosphine, dimethyl hex-2-en-4-ynedioate and arylidene N,N'-dimethylbarbituric acids in dry methylene dichloride at room temperature afforded trans-1,3-disubstituted 7,9-diazaspiro[4.5]dec-1-enes in good yields and with high diastereoselectivity. However, the similar three-component reaction with arylidene Meldrumacids resulted in a mixtures of cis/trans-1
PPh<sub>3</sub>-Catalyzed Reactions of Alkyl Propiolates with<i>N</i>-Tosylimines: A Facile Synthesis of Alkyl 2-[aryl(tosylimino)methyl]acrylate and an Insight into the Reaction Mechanism
A new PPh3‐catalyzed synthesis of alkyl2‐[aryl(tosylimino)methyl]acrylates from propiolate and N‐tosylimine has been developed. Deuterium‐labelling experiments show that the reaction mechanism involves several hydrogen‐transfer processes, which are not the turnover‐limiting step and strongly rely on the nature of the reaction media. The stable phosphonium–enamine zwitterion, which was proven to play
Palladium-Catalyzed Regio- and Stereoselective Hydrosulfonation of Propiolate Esters
作者:Shih-Ching Chuang、Selvam Raju、Pratheepkumar Annamalai、Fu-Wei Chan、Po-Yen Tseng、Po-Yen Chen、Ting-Shen Kuo
DOI:10.1055/s-0036-1588501
日期:2017.11
propiolate esters to yield alkenyl sulfonates is demonstrated. The formation of alkenyl sulfonates is highly regio- and stereoselective with favorable yields of up to 95%, and two of the alkenyl sulfonates are utilized for a Sonogashira cross-coupling reaction to produce (Z)-1,3-enynoates. An efficient palladium-catalyzed addition reaction of alkyl- and arylsulfonic acids to propiolate esters to yield