Rhodium(II)-Catalyzed Reaction of Iodonium Ylides with Conjugated Compounds: Efficient Synthesis of Dihydrofurans, Oxazoles, and Dihydrooxepines
作者:Yong Lee、Sang Yoon、Youngwan Seo、Bong Kim
DOI:10.1055/s-2004-831257
日期:——
The rhodium(II)-catalyzed reaction of iodonium ylides with a variety of conjugated compounds has been examined. With α,β-unsaturatedesters and α,β-unsaturated ketones, dihydrofurans were produced in moderate yields. Reactions with acrylonitriles yield oxazoles and dihydrofurans in moderate yields, whereas reactions with 1,3-butadienes result in dihydrofurans and dihydrooxepines in good yields, respectively
已经检查了碘鎓叶立德与各种共轭化合物的铑 (II) 催化反应。使用 α,β-不饱和酯和 α,β-不饱和酮,以中等收率生产二氢呋喃。与丙烯腈反应以中等收率产生恶唑和二氢呋喃,而与 1,3-丁二烯反应分别以良好收率产生二氢呋喃和二氢氧杂环庚烷。形成这些产物的机理途径已根据环丙烷中间体或 1,3-偶极环加成机理进行了描述。
Rhodium(II)-catalyzed Cycloaddition of Cyclic Diazodicarbonyl Compounds with Nitriles. Synthesis of Tetrahydrobenzoxazoles, Tetrahydrobenzofurans, and Tetrahydrobenzodioxoles
作者:Yong Rok Lee、Jung Yup Suk
DOI:10.3987/com-97-7881
日期:——
Iodide-Catalyzed Ring-Opening Cyclization of Cyclohexane-1,3-dione-2-spirocyclopropanes
The ring‐opening cyclization of 2′,3′‐nonsubstituted and 2′‐electron‐withdrawing group (EWG)‐substituted cyclohexane‐1,3‐dione‐2‐spirocyclopropanes was accomplished using iodide as a catalyst. The nonsubstituted derivatives afforded 3,5,6,7‐tetrahydro‐1‐benzofuran‐4(2H)‐ones in high yields in the presence of trimethylsilyl iodide at room temperature. The EWG‐substituted spirocyclopropanes, in turn, underwent