Catalytic conversion of (β,γ-unsaturated esters, amides and nitriles into γ-alkoxy or γ-hydroxy α,β-unsaturated derivatives induced by persulfate anion oxidation of diphenyl diselenide
Synthesis of optically active 4-hydroxyalk-2-enenitriles; Reaction of optically active 2-(p-chlorophenylsulfinyl)acetonitrile with aldehydes in the presence of piperidine in acetonitrile
Reaction of opticallyactive 2-(p-chlorophenylsulfinyl)acetonitrile ((R)-) with aldehydes, in the presence of piperidine in acetonitrile at r.t., gave opticallyactive 4-hydroxyalk-2-enenitriles in good optical and chemical yields. The absolute configuration of (−)-4-hydroxypent-2-enenitrile, predominantly obtained by the reaction of (R)- with propanal, was determined to be R.
作者:Fraser F. Fleming、Qunzhao Wang、Zhiyu Zhang、Omar W. Steward
DOI:10.1021/jo0258150
日期:2002.8.1
Grignard and organolithium reagents to gamma-hydroxy-alpha,beta-alkenenitriles promotes efficient conjugateadditions to what are otherwise recalcitrant Michael acceptors. Sequential deprotonation and addition of a modest excess of a second Grignard reagent allows effective conjugate delivery of alkyl groups to cyclic and acyclic alkenenitriles. Mechanistically, conjugateadditions proceed through alkylmagnesium
Chelation-controlled conjugateaddition of Grignard reagents to cyclic and acyclic gamma-hydroxyalkenenitriles stereoselectively generates beta-substituted hydroxynitriles. t-BuMgCl-induced deprotonation of gamma-hydroxyalkenenitriles followed by chloride-alkyl exchange from a second Grignard reagent, generates an alkylmagnesium alkoxide that triggers conjugateaddition. Alkylation of the resulting
Conformations of Allylic Fluorides and Stereoselectivities of Their Diels−Alder Cycloadditions
作者:Danielle Grée、Laurent Vallerie、René Grée、Loic Toupet、Ilyas Washington、Jean-Pierre Pelicier、Mercedes Villacampa、José María Pérez、K. N. Houk
DOI:10.1021/jo0016024
日期:2001.4.1
The preparations of new allylicfluorides from the corresponding alcohols are reported. Conformational analysis is achieved by comparison of experimental NMR measurements with theoretical (B3LYP) calculations of relative energies of conformers and J(H,H) and J(H,F) coupling constants. The Diels-Alder reactions of allylicfluorides are investigated experimentally and theoretically. The stereoselectivities
The rotational spectrum of the 1-cyano-3-fluoro-but-1-ene has been recorded with a pulsed-nozzle microwave Fourier transform spectrometer over the range 6-20 GHz. The frequencies were fitted to the Hamiltonian of Watson (A-reduction, I(r) representation). The resulting rotational constants are A = 7493.404(1) MHz, B = 1211.9831(2) MHz, and C = 1096.0908(1) MHz. By comparing the experimental rotational