Gold-Catalyzed Hydrophenoxylation of Propargylic Alcohols and Amines: Synthesis of Phenyl Enol Ethers
作者:Victor Laserna、Catherine Jeapes Rojas、Tom D. Sheppard
DOI:10.1021/acs.orglett.9b01208
日期:2019.6.21
A practical method for the synthesis of phenyl enol ethers is reported. The combination of a gold(I) catalyst and potassium carbonate selectively mediates the addition of phenols to propargylic alcohols/amines in a chemo-, regio-, and stereoselective fashion in high yield. The resulting enol ethers are formed exclusively with a Z-configuration and can be obtained from a wide array of phenols and propargylic
Gold-Catalyzed Hydroamination of Propargylic Alcohols: Controlling Divergent Catalytic Reaction Pathways To Access 1,3-Amino Alcohols, 3-Hydroxyketones, or 3-Aminoketones
作者:Victor Laserna、Michael J. Porter、Tom D. Sheppard
DOI:10.1021/acs.joc.9b00988
日期:2019.9.20
Alternatively, by using a catalytic quantity of aniline, 3-hydroxyketones can be obtained in high yield directly from propargylic alcohols. Further manipulation of the reaction conditions enables the selective formation of 3-aminoketones via a rearrangement/hydroamination pathway. The utility of the new chemistry was exemplified by the one-pot synthesis of a selection of N-arylpyrrolidines and N-arylpiperidines
A Dual Gold-Iron Catalysis for a One-Pot Synthesis of 2,3-Dihydroisoxazoles from Propargylic Alcohols and N-Protected Hydroxylamines
作者:Olivier Debleds、Christophe Dal Zotto、Emmanuel Vrancken、Jean-Marc Campagne、Pascal Retailleau
DOI:10.1002/adsc.200900127
日期:——
A concise one-pot route for the synthesis of 2,3-dihydroisoxazoles via a dual gold-iron catalysis has been devised. The method, based on the addition of binucleophilic protected hydroxylamine to propargylic alcohols, enables a one-pot, highly selective synthesis of these heterocycles (10 examples, up to 86% yield).
Studies on Pd(II)-Catalyzed Synthesis of (<i>Z</i>)-α-Haloalkylidene-β-lactones from Cyclocarbonylation of 2-Alkynols and the Subsequent Coupling Reactions
作者:Shengming Ma、Bin Wu、Xuefeng Jiang、Shimin Zhao
DOI:10.1021/jo0480038
日期:2005.4.1
A good regio- and stereoselectivity was observed for the PdCl2-catalyzed cyclocarbonylation of 2-alkynols with CuCl2 affording (Z)-alpha-chloroalkylidene-beta-lactons. The highly optically active (Z)-alpha-chloroalkylidene-beta-lactones could be easily prepared from the readily available optically active propargylic alcohols. The Pd(II)-catalyzed cyclocarbonylation of 2-alkynols with CuBr2 was also studied. Although the yields of (Z)-alpha-bromoalkylidene-beta-lactones were low, due to the relatively higher activity of the C-Br bond, the coupling reactions of (Z)-alpha-bromoalkylidene-beta-lactones were quite smooth to afford the corresponding products in high yields. A rationale for this reaction is discussed.
Regioselective Rapid Synthesis of Fully Substituted 1,2,3-Triazoles Mediated by Propargyl Cations
Regioselective rapid triazole syntheses at low temperature are described. Organic azides and propargyl cations generated by acids gave fully substituted 1H-1,2,3-triazoles. Most reactions could be performed in 5 min at not only rt but also -90 degrees C. Both terminal and internal alkynes were acceptable, and the sterically bulky substituents could afford the products smoothly. Various types of three-component coupling reactions were demonstrated, and the presence of allenylaminodiazonium intermediates was indicated.