Sequential hydrostannylation-cyclisation of δ- and ω-allenyl aryl halides. Cyclisation at the proximal carbon
作者:Ronald Grigg、JoséM Sansano
DOI:10.1016/0040-4020(96)00801-0
日期:1996.10
catalysed hydrostannylation of (Bu3SnH, THF, 0°C) of δ- and ω-allenylarylhalides followed by mono- or bis-cyclisation (MeCN, 80°C) affords small (5–7), large (11–17) and spirocyclic rings in which cyclisation occurs at the proximalcarbon of the orginal allene. The reaction proceeds via stereoselective allylstannane formation. The cyclisation products are α-vinyl oxygen- and nitrogen-heterocycles
Multicomponent Reductive Cross‐Coupling of an Inorganic Sulfur Dioxide Surrogate: Straightforward Construction of Diversely Functionalized Sulfones
作者:Yingying Meng、Ming Wang、Xuefeng Jiang
DOI:10.1002/anie.201911449
日期:2020.1.13
oxidants. Now, a multicomponent reductive cross-coupling involving an inorganic salt (sodium metabisulfite) for the straightforward construction of sulfones is disclosed. Both intramolecular and intermolecular reductive cross-couplings were comprehensively explored, and diverse sulfones were accessible from the corresponding alkyl and aryl halides. Intramolecular cyclic sulfones were systematically obtained
SYNTHESIS OF α-AMINO ACIDS FROM ETHYL CYANOACETATE
作者:Paul E. Gagnon、Guy Nadeau、Raymond Côté
DOI:10.1139/v52-071
日期:1952.8.1
Monosubstituted cyanoacetic esters, obtained by condensation of 1-bromo-3(s)-phenoxypropanes (s = o-Cl, o-Br, o-I, o-, m-, and p-NO2) or 1-bromo-2(s)-phenoxyethanes (s = o-Cl, o-Br, o-I, and m-NO2) with ethylcyanoacetate by means of potassium carbonate, were transformed through a Curtius degradation into cyanoacetisocyanates. These compounds by hydrolysis in acid or alkaline medium gave α-amino acids. However
We report the heteroannulations of bicyclobutane derivatives bearing enol ether groups in the presence of H2O under mild conditions. The reaction affords spirocyclobutanes with cyclic acetal groups via the Au-catalyzed hydration of the enol ether group and subsequent intramolecular cyclization.
我们报告了在温和条件下存在 H 2 O 的情况下带有烯醇醚基团的双环丁烷衍生物的杂环化。该反应通过烯醇醚基的 Au 催化水合和随后的分子内环化反应得到具有环状缩醛基团的螺环丁烷。