presence of a catalytic amount of a rhenium or manganese complex gives ring‐expanded and carbon‐chain extension products, respectively. In these reactions, alkynes insert into a non‐strained carbon–carbonsinglebond of 1,3‐dicarbonyl compounds. The ring‐expansion reaction is also promoted by the addition of 4‐Å molecular sieves instead of a catalytic amount of an isocyanide.
Rhenium- and manganese-catalyzedreactions between beta-keto esters and acetylenes, followed by treatment with tetrabutylammonium fluoride, gave 2-pyranone derivatives regioselectively.
β-酮酸酯和乙炔之间的R和锰催化反应,然后用氟化四丁基铵处理,区域选择性地生成2-吡喃酮衍生物。
Indium-Catalyzed 2-Alkenylation of 1,3-Dicarbonyl Compounds with Unactivated Alkynes
the position of C-C bond formation on the acetylene moiety. In most of the cases, the reaction requires less than 1-mol % loading of the catalyst and does not require solvent. The reaction tolerates a wide variety of functional groups including ester, ether, allylic halide, furan, thiophene, and protected amine. Experimental and theoretical studies suggested that the reaction proceeds via a concerted
Indium (III) mediated Markovnikov addition of malonates and β-ketoesters to terminal alkynes and the formation of Knoevenagel condensation products
作者:Ji Zhang、Peter G. Blazecka、Paul Angell、Mark Lovdahl、Timothy T. Curran
DOI:10.1016/j.tet.2005.05.065
日期:2005.8
active methylene compounds to terminal alkynes has been expanded to use malonates and low boiling terminal alkynes to form the Markovnikov addition products. Indium(III) chloride and indium(III) bromide were also found to be efficient catalysts. Knoevenagelcondensation products were isolated when reactions involved a simple malonate or β-ketoester.
Indium-Catalyzed Addition of Active Methylene Compounds to 1-Alkynes
作者:Masaharu Nakamura、Kohei Endo、Eiichi Nakamura
DOI:10.1021/ja038006m
日期:2003.10.1
An activemethylenecompound adds to a 1-alkyne in high to quantitative yield upon heating in the presence of 0.05-5 mol % of In(OTf)3 to give an alpha-alkenylated carbonyl compound.