Gold-Catalyzed Oxidative Reactions of Propargylic Carbonates Involving 1,2-Carbonate Migration: Stereoselective Synthesis of Functionalized Alkenes
作者:Ning Sun、Ming Chen、Yuanhong Liu
DOI:10.1021/jo500573s
日期:2014.5.2
A gold-catalyzed oxidative reaction of propargylic carbonates or acetates using 3,5-dichloropyridine as the oxidant has been developed. The reaction provides efficient access to α-functionalized-α,β-unsaturated ketones with excellent regio- and diastereocontrol via a regioselective attack of the N-oxide to the gold-activated alkyne followed by a 1,2-carbonate migration. In addition, the alkene products
We report on a study of copper-catalyzed alkylation of internal allylic carbonates using functionalized alkyl and aryl Grignardreagents. The reactions exhibit good regioselectivity for either SN2 or SN2′ products, enabling the preparation of products with E-alkene selectivity. Density functional theory (DFT) calculations reveal the origins of the regioselectivity based on the different behaviors of
我们报告了使用官能化烷基和芳基格氏试剂铜催化内烯丙基碳酸酯烷基化的研究。该反应对S N 2 或S N 2' 产物表现出良好的区域选择性,使得能够制备具有E-烯烃选择性的产物。密度泛函理论(DFT)计算揭示了基于同铜酸盐和异铜酸盐的不同行为的区域选择性的起源。
Yoshikawa, Takashi; Mori, Seiji; Shindo, Mitsuru, Journal of the American Chemical Society, 2009, vol. 131, p. 2092 - 2093
作者:Yoshikawa, Takashi、Mori, Seiji、Shindo, Mitsuru
DOI:——
日期:——
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.
Mild and Efficient Synthesis of (<i>Z</i>)-α-Chloroalkylidene-β-lactones via the PdCl<sub>2</sub>-Catalyzed Cyclocarbonylation of 2-Alkynols
作者:Shengming Ma、Bin Wu、Shimin Zhao
DOI:10.1021/ol0357245
日期:2003.11.1
A mild and efficient methodology involving PdCl2-catalyzed cyclocarbonylation of 2-alkynols with CuCl2 for the synthesis of (Z)-alpha-chloroalkylidene-beta-lactones was developed. Using the readily available optically active propargylic alcohols allows convenient synthesis of the corresponding (Z)-alpha-chloroalkylidene-beta-lactones with high ee values. cis-Chloropalladation was observed as the major pathway, which is unique as compared to the reported data.