The cobalt-catalyzed carboxylation of propargyl acetates with CO2 (1 atm) is described. The reaction proceeds at room temperature in the presence of Mn powder as a reducing reagent. Various propargyl acetates are converted to the corresponding carboxylic acids in good to high yields.
Metal-Free Transfer Hydroiodination of C–C Multiple Bonds
作者:Weiqiang Chen、Johannes C. L. Walker、Martin Oestreich
DOI:10.1021/jacs.8b12318
日期:2019.1.16
The design and a gram-scalesynthesis of a bench-stable cyclohexa-1,4-diene-based surrogate of gaseous hydrogen iodide are described. By initiation with a moderately strong Brønsted acid, hydrogen iodide is transferred from the surrogate onto C-C multiple bonds such as alkynes and allenes without the involvement of free hydrogen iodide. The surrogate fragments into toluene and ethylene, easy-to-remove
描述了基于环己-1,4-二烯的气态碘化氢替代品的设计和克级合成。通过用中等强度的布朗斯台德酸引发,碘化氢从替代物转移到 CC 多重键上,例如炔烃和丙二烯,而没有游离碘化氢的参与。代用品碎片化为甲苯和乙烯,易挥发废物。这种氢碘化反应避免了对碘化氢或氢碘酸的不稳定处理。通过这种方式,可以以立体控制的方式访问范围广泛的以前未知或难以制备的乙烯基碘。
A Novel Three-Component Reaction of Allenoates, Isocyanides, and Carboxylic Acids: Facile Synthesis of Highly Substituted Acryl Imide Derivatives
作者:Xian Huang、Feng Sha
DOI:10.1021/jo702382h
日期:2008.2.1
A novel synthesis of highly substituted acryl imide derivatives by the three-component reaction of allenoates, isocyanides, and carboxylicacids was reported, and the intramolecular cyclization reaction of allenoic acids with isocyanides was also described.
Metal-Free Transfer Hydrobromination of C–C Triple Bonds
作者:Weiqiang Chen、Martin Oestreich
DOI:10.1021/acs.orglett.9b01431
日期:2019.6.21
A transfer hydrobromination of C–C triplebonds inititated by Brønsted acids is reported. Hydrogen bromide is released stepwise from a bench-stable cyclohexa-1,4-diene-based surrogate, generating biphenyl and ethylene as waste. A range of vinyl bromides was prepared from terminal and internal, mainly acceptor-substituted alkynes with good functional-group tolerance.
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。