An Atom-Economical Access to β-Heteroarylated Ketones from Propargylic Alcohols via Tandem Ruthenium/Indium Catalysis
作者:Barry M. Trost、Alexander Breder
DOI:10.1021/ol102706j
日期:2011.2.4
The direct and chemoselective synthesis of β-heteroarylated ketonesfrom secondary propargyl alcohols through tandem Ru/In catalysis is reported. Both electron-rich and neutral heteroarenes, such as furans and indoles, efficiently undergo the redox isomerization/conjugate addition (RICA) sequence to provide the corresponding adducts in yields of up to 97%.
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.