A new, highly stereoselective approach to pyrrolidines via overall 5-endo-trig cyclisations of homoallylic tosylamides
作者:Andrew D. Jones、David W. Knight
DOI:10.1039/cc9960000915
日期:——
Iodocyclisations of E-homoallylic tosylamides 7 lead to excellent yields of either 2,5-trans-or 2,5-cis-3-iodopyrrolidines (10 or 11), depending upon the reaction conditions.
Indirect Electroreductive Sequential Radical Reaction Catalyzed by a Ni(II) Complex. One-Step Preparation of Functionalized (Methylene)cyclopentanes.
作者:Shigeko OZAKI、Shizue MITOH、Hidenobu OHMORI
DOI:10.1248/cpb.43.1435
日期:——
Substituted (methylene)cyclopentanes were prepared by one-step reaction at room temperature from butynyl iodides and activated olefins by sequencing of free radical addition and cyclization reactions. The reactions, which were conducted by indirect electroreduction catalyzed by a nickel(II) complex, proceeded with modest selectivity for formation of the Z(methylene)cyclopentanes.
CO<sub>2</sub>-Activation for γ-Butyrolactones and Its Application in the Total Synthesis of (±)-Heteroplexisolide E
作者:Suhua Li、Shengming Ma
DOI:10.1002/asia.201200467
日期:2012.10
is described. The catalyst is highly active and can be applied for the synthesis of (optically active) mono‐ or bicyclic α‐alkylidene‐γ‐butyrolactones with excellent regio‐ and stereoselectivity and good functional group tolerance. The potential of the reaction has been demonstrated in the first synthesis of (±)‐heteroplexisolide E.
Room temperature syntheses of entirely diverse substituted β-fluorofurans
作者:Yan Li、Kraig A. Wheeler、Roman Dembinski
DOI:10.1039/c1ob06693e
日期:——
Synthesis of highlysubstituted 3-fluorofurans is reported. The sequence began with preparation of tert-butyldimethylsilyl alk-1-en-3-yn-1-yl ethers from 1,4-disubstituted alk-3-yn-1-ones. Subsequent fluorination of alkenynyl silyl ethers with Selectfluor gave 2-fluoroalk-3-yn-1-ones in almost quantitative yield. Subsequent 5-endo-dig cyclizations using chlorotriphenylphosphine gold(I)/silver trif
A novel Cu-catalyzed intramolecular aryl-etherification reaction of alkoxyl alkynes with diaryliodonium salts is realized. The reactions proceed smoothly to produce valuable oxo-heterocycles with readily available linear starting materials via cleavage of a stable C-O bond.