An Efficient Approach for Monofluorination via Aqueous Fluorolactonization Reaction of 2,3-Allenoic Acids with Selectfluor
摘要:
[GRAPHICS]We have developed a convenient method for the efficient monofluorination via the electrophilic fluorocyclization reaction of 2,3-allenoic acids with Selectfluor in MeCN in the presence of 10 equiv of H2O or even in pure water to afford beta-fluorobutenolides in moderate to high yields.
Palladium Acetate-Catalyzed Cyclization Reaction of 2,3-Allenoic Acids in the Presence of Simple Allenes: An Efficient Synthesis of 4-(1‘-Bromoalk-2‘(<i>Z</i>)-en-2‘-yl)furan-2(5<i>H</i>)-one Derivatives and the Synthetic Application
作者:Zhenhua Gu、Xinke Wang、Wei Shu、Shengming Ma
DOI:10.1021/ja072790j
日期:2007.9.1
We have realized a cyclizationreaction of 2,3-allenoicacids 1 in the presence of simple alkyl- or aryl-substituted allenes 3. In this reaction, the cyclic oxypalladation of 2,3-allenoicacid with Pd(II) would afford the furanonyl palladium intermediate 2, which could be trapped by the simple allene to afford a pi-allylic intermediate anti-9. This intermediate anti-9 could be nucleophilically attacked
PdCl<sub>2</sub>-Catalyzed Two-Component Cross-Coupling Cyclization of 2,3-Allenoic Acids with 2,3-Allenols. An Efficient Synthesis of 4-(1‘,3‘-Dien-2‘-yl)-2(5<i>H</i>)-furanone Derivatives
作者:Shengming Ma、Zhenhua Gu
DOI:10.1021/ja0500815
日期:2005.5.1
Cross-coupling cyclization reaction between 2,3-allenoic acids 1 and 2,3-allenols 2, in which two allenes functioned differently, was realized to afford 4-(1',3'-dien-2'-yl)-2(5H)-furanone derivatives3. The reaction may proceed via an oxypalladation, insertion, and beta-hydroxide elimination process. A high E-stereoselectivity of the new formed C=C double bond was observed.
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
Pd(II)-Catalyzed Coupling Cyclization of 2,3-Allenoic Acids with Allylic Halides. An Efficient Methodology for the Synthesis of β-Allylic Butenolides
作者:Shengming Ma、Zhanqian Yu
DOI:10.1021/jo034511q
日期:2003.8.1
An effective method for the synthesis of beta-allyl polysubstituted butenolides from the easily available allylic halides and 2,3-allenoicacids is described. By using this method optically active butenolides can be obtained. According to the results presented in this paper, the reaction may proceed via three consecutive steps: cyclic oxypalladation of the allene, insertion of the C=C bond in allylic
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。