Chemoselective 1,3-dipolar cycloadditions of azomethine ylide with conjugated dienes
作者:Laura C. Blumberg、Brian Costa、Rebecca Goldstein
DOI:10.1016/j.tetlet.2010.12.042
日期:2011.2
pyrrolidines, versatile building blocks for our drug discovery efforts. The 1,3-dipolar cycloaddition between activated olefins and nonstabilized azomethine ylide is a known method for synthesizing pyrrolidines in a stereospecific manner. Steric and electronic effects on the chemoselectivity of the 1,3-dipolar cycloaddition between azomethine ylide and α,β,γ,δ-unsaturated carboxylates have been explored.
Vinyl Nosylates: An Ideal Partner for Palladium-Catalyzed Cross-Coupling Reactions
作者:Nicolas P. Cheval、Anna Dikova、Aurélien Blanc、Jean-Marc Weibel、Patrick Pale
DOI:10.1002/chem.201300127
日期:2013.7.1
In a hurry to leave! Nosylates act as an excellent leavinggroup in various palladium‐catalyzed cross‐couplings, such as Suzuki, Stille, Heck, and Sonogashira reactions (see scheme). Crystalline, stable, and cheap vinyl and aryl nosylates proved better than classical halides and triflates, consistently giving higher yields of coupling products. Their usefulness in CCbondformation was also demonstrated
Further support to the hypothesis that antimutagenic activities of α, β-unsaturated carbonyl compounds against UV-induced mutagenesis of E. coli may be due to an interaction with thiol groups were obtained by an experiment with the supplement of glatathione to the assay medium. Antimutagenic activity against MNNG induced mutation was also observed.
Short Enantioselective Total Syntheses of <i>trans</i>-Clerodane Diterpenoids: Convergent Fragment Coupling Using a <i>trans</i>-Decalin Tertiary Radical Generated from a Tertiary Alcohol Precursor
作者:Yuriy Slutskyy、Christopher R. Jamison、Gregory L. Lackner、Daniel S. Müller、André P. Dieskau、Nicholas L. Untiedt、Larry E. Overman
DOI:10.1021/acs.joc.6b00697
日期:2016.8.19
strategy for the enantioselective total synthesis of trans-clerodane diterpenoids is described. The key bond construction is accomplished by 1,6-addition of a trans-decalin tertiary radical with 4-vinylfuran-2-one. The tertiary radical is optimally generated from the hemioxalate salt of the corresponding tertiary alcohol upon activation by visible light and an Ir(III) photoredox catalyst. The enantioselective
Non-stabilized azomethine ylides in [3 + 2] cycloadditions. Pyrrolidinylfuranones from (5S )-5-menthyloxy-4-vinylfuran-2(5H )-one
作者:Kai Gerlach、H. M. R. Hoffmann、R. Wartchow
DOI:10.1039/a803693d
日期:——
Upon sonication with lithium fluoride in acetonitrile N-benzyl-N-methoxymethyl(trimethylsilylmethyl)amines 9a–c undergo chemoselective 1,3-dipolar cycloaddition with 4-vinylfuranones 2 and 6 to afford pyrrolidinylfuranones 10, 11a–c and 12a–c. The stereochemistry is assigned by X-ray analyses and proton NMR data comparison of related oxiranylfuranone 13.