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.
Mild and efficient palladium(<scp>ii</scp>)-catalyzed racemization of allenes
作者:Attila Horváth、Jan-E. Bäckvall
DOI:10.1039/b316482a
日期:——
Allenes undergo racemization in the presence of catalytic amounts of Pd(OAc)2/LiBr under mild conditions; the reaction proceeds via a bromopalladation–debromopalladation sequence and tolerates various functional groups.
Studies on the Tandem Reaction of 4-Aryl-2,3-allenoates with Organozinc Reagents: A Facile Route to Polysubstituted Naphthols
作者:Guobi Chai、Zhan Lu、Chunling Fu、Shengming Ma
DOI:10.1002/chem.200901779
日期:2009.10.26
Diversified polysubstituted α‐naphthols have been efficiently constructed through a tandem reaction of easily available 2,3‐allenoates and organozinc reagents in moderate to excellent yields (see scheme). Some of the products may undergo a couple of sequential coupling reactions to afford polysubstituted naphthalenes.
CuCl-catalyzed stereoselective conjugate addition of Grignard reagents to 2,3-allenoates
作者:Jian He、Zhan Lu、Guobi Chai、Chunling Fu、Shengming Ma
DOI:10.1016/j.tet.2012.01.027
日期:2012.3
CuCl was found to be an efficient catalyst for the conjugateaddition of 2,3-allenoates with Grignardreagents to synthesize poly-substituted β,γ-unsaturated alkenoates with high stereoselectivity in good to excellent yields. Primary, secondary, and tertiary alkyl, vinyl or phenyl Grignardreagents may all be used.
Iron-Catalyzed Highly Regio- and Stereoselective Conjugate Addition of 2,3-Allenoates with Grignard Reagents
作者:Zhan Lu、Guobi Chai、Shengming Ma
DOI:10.1021/ja075750o
日期:2007.11.28
An efficient highly regio- and stereoselective iron-catalyzed conjugate addition of 2,3-allenoates with primary or secondary alkyl, phenyl, or vinyl Grignardreagents to synthesize multi-substituted β,γ-unsaturated enoates has been reported. The in situ formed magnesium dienolate may readily react with different electrophilic reagents to construct an allylic quaternary carbon at the α-position of the