Silver(I)-Catalyzed Aminocyclization of 2,3-Butadienyl and 3,4-Pentadienyl Carbamates: An Efficient and Stereoselective Synthesis of 4-Vinyl-2-oxazolidinones and 4-Vinyltetrahydro-2H-1,3-oxazin-2-ones
novel three-component reaction of alkadienol, CO2, and aryl or vinylic halide gives a vinyl group-substituted cyclic carbonate in one pot in the presence of a catalytic amount of a palladium complex. 2,3-Alkadienol affords five-membered ring carbonate in good yield, while 3,4-alkadienol effects the six-membered one successfully. 2,4-Alkadienol also takes part in this reaction to provide five-membered
The regio- and stereochemical course of reductive cross-coupling reactions between 1,3-disubstituted allenes and vinylsilanes: synthesis of (Z)-dienes
作者:Allan U. Barlan、Glenn C. Micalizio
DOI:10.1016/j.tet.2010.02.062
日期:2010.6
control is attained by employing allenic alkoxides, where the proximal heteroatom dictates the site-selectivity in a process that proceeds by net formal metallo-[3,3] rearrangement (directed carbometalation/elimination). Stereoselectivity in these reactions is complex, with both the nature of allene substitution and relative stereochemistry of the substrate impacting the stereoselective generation of each
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.
Gold(I)-Catalyzed Isomerization of Allenyl Carbinol Esters: An Efficient Access to Functionalized 1,3-Butadien-2-ol Esters
作者:Andrea K. Buzas、Florin M. Istrate、Fabien Gagosz
DOI:10.1021/ol063031t
日期:2007.3.1
A study concerning the gold(I)-catalyzed rearrangement of diversely substituted allenyl carbinol esters into functionalized 1,3-butadien-2-ol esters is described. The mild conditions employed allow the efficient, rapid, and stereoselective synthesis of a variety of such compounds via a new 1,3-shift of an ester moiety onto a gold-activated allene. [structure: see text]
PdCl<sub>2</sub>/NaI-Catalyzed Homodimeric Coupling-Cyclization Reaction of 2,3-Allenols: An Efficient Synthesis of 4-(1‘,3‘-Dien-2‘-yl)-2,5-dihydrofuran Derivatives
作者:Youqian Deng、Yihua Yu、Shengming Ma
DOI:10.1021/jo702332m
日期:2008.1.1
A PdCl2/NaI-catalyzed homodimeric coupling-cyclizationreaction of 2,3-allenols was observed to provide an efficient route to 4-(1‘,3‘-dien-2‘-yl)-2,5-dihydrofuranderivatives. By using the easily available optically active starting materials, 2,5-dihydrofurans with high enantiopurity may be prepared. A Pd(II)-catalyzed mechanism was also discussed.