A robust transition-metal-free one-step strategy for the synthesis of ynamides from sulfonamides and (Z)-1,2-dichloroalkenes or alkynyl chlorides is presented. This method is not only effective for internal ynamides but also amenable for terminal ynamides. Various functional groups, even the vinyl moiety, are compatible, and thus, this strategy offers the opportunity for further functionalization.
Au-Catalyzed Stereoselective Ritter Reaction of Haloalkynes with Nitriles for (<i>Z</i>
)-<i>β</i>
-Halogenated Enamides
作者:Congrong Liu、Fulai Yang
DOI:10.1002/ejoc.201901318
日期:2019.10.31
An efficient and stereoselective protocol has been developed for the synthesis (Z)‐β‐Halogenated enamide via gold catalyzed Ritter reaction. In the presence of 2 mol‐% BrettPhosAuCl and 2 mol‐% AgNTf2, a broad range of nitriles smoothly underwent Ritter reaction with aromatic, vinylic or aliphatic haloalkynes to give structurally diverse (Z)‐β‐Halogenated enamides in excellent to good yields.
Benign catalysis with zinc: atom-economical and divergent synthesis of nitrogen heterocycles by formal [3 + 2] annulation of isoxazoles with ynol ethers
作者:Xin-Qi Zhu、Han Yuan、Qing Sun、Bo Zhou、Xiao-Qin Han、Zhi-Xin Zhang、Xin Lu、Long-Wu Ye
DOI:10.1039/c8gc02051e
日期:——
zinc-catalyzed formal [3 + 2] annulation of isoxazoles with ynol ethers under exceptionally mild reaction conditions, leading to the atom-economical and divergent synthesis of 2-alkoxyl 1H-pyrroles and 3H-pyrroles, respectively. Importantly, this zinc-catalyzed protocol demonstrates the dramatically divergent reactivity from the relevant platinum catalysis, where the formal [4 + 2] annulation of isoxazoles with
Gold(I)-Catalyzed Chloroalkynylation of 1,1-Disubstituted Alkenes via 1,3-Chlorine Shift: A Combined Experimental and Theoretical Study
作者:Mathis Kreuzahler、Gebhard Haberhauer
DOI:10.1021/acs.joc.9b01371
日期:2019.6.21
achieved via gold(I) catalysis. The key step in the reaction mechanism is a 1,3-chlorine shift to a cationic center, leading selectively to the corresponding homopropargyl chlorides. As this gold(I)-catalyzed addition can be conducted on a preparative scale and tolerates a broad substrate scope of both alkyne and alkene reactants, the presented chloroalkynylation reaction is an attractive method en route
Ligand exchange reaction of sulfoxides in organic synthesis: A novel method for synthesizing acetylenes and allenes from carbonyl compounds through sulfoxides having a trifluoro-methanesulfonyloxy group on the β-carbon
A novel method for synthesizing acetylenes and allenes from carbonyl compounds is described. Ligand exchange reaction of alkenylsulfoxides having a trifluoromethanesulfonyloxy group on the β-carbon, which were derived from α-alkyl β-ketosulfoxides, with n-BuLi gave disubstituted acetylenes in good yields. In the case of alkenylsulfoxides having both the trifluoromethanesulfonyloxy and aryl groups on