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
Ferric Chloride Hexahydrate-Catalyzed Highly Regio- and Stereoselective Conjugate Addition Reaction of 2,3-Allenoates with Grignard Reagents: An Efficient Synthesis of β,γ-Alkenoates
作者:Guobi Chai、Zhan Lu、Chunling Fu、Shengming Ma
DOI:10.1002/adsc.200900091
日期:2009.8
Ferricchloride hexahydrate was shown to be an efficient catalyst for the conjugate addition of 2,3-allenoates with alkyl-, aryl-, or vinyl-Grignard reagents to synthesize polysubstituted β,γ-unsaturated alkenoates with high regio- and stereoselectivity. The in situ formed magnesium dienolate may readily react with different electrophilic reagents under different reaction conditions with or without
From allene to allene: a palladium-catalyzed approach to β-allenyl butenolides and their application to the synthesis of polysubstituted benzene derivatives
作者:Shengming Ma、Zhenhua Gu、Youqian Deng
DOI:10.1039/b513371h
日期:——
carbonates catalyzed by Pd(OAc)2-TFP has been developed; the products were applied successfully to the Diels-Alder reaction with electron-deficient alkynes to afford polysubstitutedbenzenederivatives with an excellent regioselectivity.
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