Metal-Catalyzed Cycloisomerization Reactions of <i>cis</i>-4-Hydroxy-5-alkynylpyrrolidinones and <i>cis</i>-5-Hydroxy-6-alkynylpiperidinones: Synthesis of Furo[3,2-<i>b</i>]pyrroles and Furo[3,2-<i>b</i>]pyridines
作者:Jasmine C. Jury、Nalivela Kumara Swamy、Arife Yazici、Anthony C. Willis、Stephen G. Pyne
DOI:10.1021/jo9007942
日期:2009.8.7
Furo[3,2-b]pyrroles and furo[3,2-b]pyridines can be conveniently prepared in good yields from the cycloisomerization reactions of cis-4-hydroxy-5-alkynylpyrrolidinones and cis-5-hydroxy-6-alkynylpiperidinones, respectively, using Ag(I), Pd(II)/Cu(I), or Au(I) catalysis. In one case, the cycloisomerization product was unstable and produced a furanderivative by a ring-opening reaction.
顺式-4-羟基-5-炔基吡咯烷酮与顺式-5-羟基-6-炔基哌啶子酮的环异构化反应可方便地以高收率制备呋喃并[3,2- b ]吡咯和呋喃[3,2- b ]吡啶分别使用Ag(I),Pd(II)/ Cu(I)或Au(I)催化。在一种情况下,环异构化产物不稳定并且通过开环反应产生呋喃衍生物。
<i>N</i>-Trialkylsilyl Bistrifluoromethanesulfonimides (R<sub>3</sub>SiNTf<sub>2</sub>) Are Powerful Catalysts for the Highly Efficient α-Amido Alkylation Reactions of Silicon-Based Nucleophiles
作者:Raja Ben Othman、Till Bousquet、Mohamed Othman、Vincent Dalla
DOI:10.1021/ol052357j
日期:2005.11.1
In situ formed N-trialkylsilyl bistrifluoromethanesulforlimides (R3SiNTf2) species have been shown to efficiently catalyze the nucleophilic substitution reactions of chiral 5-oxypyrrolidin-2-ones by silicon-based nucleophiles. The reaction rates were significantly accelerated in comparison to the cases where the usual triflate catalysts are used. Adducts were obtained in high yields and usual stereoselectivities within short reaction times, and the process was compatible with a semipreparative scale.
Addition of a Chiral Boron Enolate to Cyclic <i>N</i>-Acyliminium Ions. Stereocontrolled Synthesis of the Pyrrolizidine Ring System