General Zinc-Catalyzed Conia-Ene Reactions of 1,3-Dicarbonyl Compounds with Alkynes Including the Classically Challenging Substrates under Neat Conditions
作者:Chen-Liang Deng、Ren-Jie Song、Yi-Lin Liu、Jin-Heng Li
DOI:10.1002/adsc.200900588
日期:2009.12
products has been developed by zinc-catalyzed intramolecular Conia-enereactions of 1,3-dicarbonylcompounds with alkynes. This new route allows a wide range of dicarbonyl compounds, including the classicallychallenging 1,3-diesters and N,N′-disubstituted 1,3-keto amides, to be used for the Conia-enereaction with inexpensive zinc chloride (ZnCl2) underneatconditions.
Iron (III) salts (perchlorate and nitrate nonahydrate) in acetonitrile or acetic anhydride at 0–50°C oxidize the ∝-position of malonic esters efficiently via the corresponding radicals. In the presence of olefins and aromatics, inter- and intramolecular free radical chain or oxidative additions are observed.
Cu(I)-Catalyzed Intramolecular C−C Coupling of Activated Methylene Compounds with Vinyl Halides: Efficient Synthesis of Functionalized Alkylidenecyclobutanes
作者:Liqun Chen、Min Shi、Chaozhong Li
DOI:10.1021/ol802012q
日期:2008.11.20
With the catalysis of CuI/L-proline, a number of 2-(3-bromobut-3-enyl)malonates underwent efficient intramolecularC-vinylation leading to the synthesis of functionalized alkylidenecyclobutanes. Competition experiments revealed that this four-membered ring closure is fundamentally preferred over the corresponding five-membered ring closure.
Synthesis of a <i>C</i><sub>2</sub>-Symmetric Chiral Borinic Acid and Its Application in Catalytic Desymmetrization of 2,2-Disubstituted-1,3-Propanediols
作者:Jian Song、Wen-Hua Zheng
DOI:10.1021/jacs.3c02331
日期:——
synthesis of efficient chiral boronic acids remains a formidable challenge. Herein we disclose a rational design and a concise synthesis of a series of novel C2-symmetric disubstituted boronic acids, or borinic acids. Chiral borinic acids have been found to be excellent agents that can achieve highly enantioselective desymmetrization of 2,2-disubstituted-1,3-propanediols, providing chiral diols with a quaternary