Efficient Synthesis of 3-Chloromethyl-2(5<i>H</i>)-furanones and 3-Chloromethyl- 5,6-dihydropyran-2-ones via the PdCl<sub>2</sub>-Catalyzed Chlorocyclocarbonylation of 2,3- or 3,4-Allenols
作者:Xin Cheng、Xuefeng Jiang、Yihua Yu、Shengming Ma
DOI:10.1021/jo8015677
日期:2008.11.21
was formed between the center carbon atom of the allene moiety and the hydroxyl oxygen, which was established by the X-ray single crystal diffraction study of gamma-lactone 3p. The highly opticallyactive 3-chloromethyl-2(5H)-furanones could be easily prepared from the readily available opticallyactive 2,3-allenols. A mechanism for this reaction was proposed.
An Efficient Synthesis of Terminal Allenes from Terminal 1-Alkynes
作者:Jinqiang Kuang、Shengming Ma
DOI:10.1021/jo802391x
日期:2009.2.20
We have developed a modified method for the synthesis of terminalallenesfromterminal 1-alkyne: The reaction of 1-alkynes with 1.8 equiv of Cy2NH and 2.5 equiv of paraformaldehyde mediated by CuI (0.5 equiv) in refluxing dioxane may produce terminalallenes in much higher yields than the previously reported protocol and many functional groups such as mesylate, hydroxyl group, ether, amide, etc. may
Game, set, and match: The first regio‐ and enantioselective version of the title reaction is described. The chiral catalyst prepared in situ from CrCl3 and a non‐C2‐symmetric bis(oxazoline) ligand 1 affords the valuable chiral β‐allenols regioselectively in good yields with excellent ee values. R=aryl, alkyl.
Palladium-Catalyzed Three-Component Transformation of Homoallenols: A Regio- and Stereoselective Route to 1,5-Amino Alcohols
作者:Miriam Aylward、Vincent Coeffard、Patrick J. Guiry
DOI:10.1021/jo1025628
日期:2011.5.6
A palladium-catalyzed three-component transformation of enantioenriched homoallenols with aryl halides and amines has been developed to selectively afford (Z)-configured 1,5-amino alcohols in good-to-excellent yields without any epimerization.
Stereodivergent Palladium- and Rhodium-Catalyzed Intramolecular Addition of Tosylureas to Allenes: Diastereoselective Synthesis of Tetrahydropyrimidinones
作者:Arne G. A. Geissler、Jasmin R. Riesterer、Bernhard Breit
DOI:10.1021/acs.orglett.1c03482
日期:2021.12.3
palladium or rhodium-based catalytic system and affords 1,3-cyclic ureas. Under palladium catalysis a range of thermodynamic anti-tetrahydropyrimidinones are accessible, while rhodium catalysis allows synthesis of the kinetic syn-tetrahydropyrimidinones. For a representative scope of substrates both cyclic ureas were obtained in excellent yields and diastereoselectivities. The obtained tetrahydropyrimidinones