Efficient Assembly of Chromone Skeleton from 2,3-Allenoic Acids and Benzynes
作者:Guobi Chai、Youai Qiu、Chunling Fu、Shengming Ma
DOI:10.1021/ol202076c
日期:2011.10.7
Chromone derivatives were synthesized from 2,3-allenoicacids and benzynes in moderate to excellent yields under mild conditions. Instead of the cyclic conjugate addition of the intermediate A formed by the nucleophilic addition of allenoic acid with benzyne, this intermediate undergoes 1,2-addition with the carbonyl group, which was followed by the ring opening, conjugate addition, and protonolysis
The efficient copper-catalyzed sulfenylation and selenylation of 2,3-allenoic acids with disulfides or diselenides were developed, respectively. These reactions proceeded through tandem radical addition/intramolecular cyclization processes, affording a series of 4-sulfenylated and 4-selenylated butenolides in moderate to excellent yields. Moreover, 4-sulfonylated butenolides could also be obtained
3-allenoic acids with AgSCF3 in the presence of (NH4)2S2O8 and catalytic copper salt was investigated. A series of 4-aryl-2,3-allenoic acids underwent radical trifluoromethylthiolation/intramolecular cyclization to afford β-trifluoromethylthiolated butenolides, which were conveniently transformed into trifluoromethylthiolated furan derivatives. In contrast, 2-monosubstituted 2,3-allenoic acids were converted
研究了在(NH 4)2 S 2 O 8和催化铜盐存在下,AgSCF 3对2,3-烯丙基酸的氧化三氟甲基硫醇化反应。一系列的4-芳基-2,3-烯丙酸经过自由基三氟甲基硫醇化/分子内环化反应,得到β-三氟甲基硫醇化的丁烯化物,将其方便地转化为三氟甲基硫醇化的呋喃衍生物。相反,在相似的反应条件下,将2-单取代的2,3-烯丙酸转化成相应的3,4-双(三氟甲硫基)丁-2-烯酸。
Copper(II)-Catalyzed Reaction of 2,3-Allenoic Acids, Sulfur Dioxide, and Aryldiazonium Tetrafluoroborates: Route to 4-Sulfonylated Furan-2(5<i>H</i>)-ones
作者:Kaida Zhou、Jun Zhang、Guanyinsheng Qiu、Jie Wu
DOI:10.1021/acs.orglett.8b03718
日期:2019.1.4
A copper(II)-catalyzed three-component reaction of 2,3-allenoic acids, sulfur dioxide, and aryldiazonium tetrafluoroborates under mild conditions is developed, leading to 4-sulfonylated furan-2(5H)-ones in good yields. Not only sodium metabisulfite but also 1,4-diazabicyclo[2.2.2]octane-sulfur dioxide (DABCO·(SO2)2) is workable under the conditions. This transformation proceeds through a radical process
An iron-catalyzed three-component cyanoalkylsulfonylation of 2,3-allenoic acids, K2S2O5, and the ring-opening of cyclobutanone oximeesters is described. The radical tandem cyclization route allows access to diverse cyanoalkylsulfonylated butenolides in moderate to good yields under mild conditions. Moreover, the products are further converted, offering the corresponding derivatives.
描述了铁催化的 2,3-丙二烯酸、K 2 S 2 O 5 的三组分氰基烷基磺酰化和环丁酮肟酯的开环。自由基串联环化路线允许在温和条件下以中等至良好的产率获得各种氰基烷基磺酰化丁烯内酯。此外,产品进一步转换,提供相应的衍生产品。