One-Pot Preparation of α-Cyanovinyl Ethers (2-Alkoxy-2-alkenenitriles) from Vinyl Ethers: Elaboration to 3-Alkoxy-2-oxo-3-alkenenitriles and Aluminium Chloride-Catalyzed Cycloadditions to Cyclopentadiene
Photoinduced molecular transformations. Part 145. Regioselective [3 + 2] photoadditions of 2-hydroxyphenanthrene-1,4-dione with electron-rich alkenes and phenylacetylene: new one-step synthesis of 9,10-dihydrophenanthro[2,3-b]furan-7,11-diones and 2-phenylphenanthro[2,3-b]furan-7,11-dione
regioselective [3 + 2] photoaddition in 25–50% yields. A [3 + 2] photoadduct, 9-phenylphenanthro[2,3-b]furan-7,11-dione, can be similarly formed in low yield when 2-hydroxyphenanthrene-1,4-dione and phenylacetylene in acetone are irradiated with Pyrex-filtered light. In contrast, the irradiation of 2-hydroxyphenanthrene-1,4-dione and alkenes such as methyl acrylate, acrylonitrile, cyclohexene, isopropenyl acetate
A Novel Method of Crossed-Aldol Condensation: Alkylation of Trimethylsilyl Enol Ethers by Alkyl 1-Chloro-2-arylthioalkyl Ethers
作者:M. A. Ibragimov、M. I. Lazareva、W. A. Smit
DOI:10.1055/s-1985-31370
日期:——
Trimethylsilyl enol ethers 5, derived from aldehydes or ketones, react with alkyl 1-chloro-2-arylthioalkyl ethers 3 (β-arylthio-α-chloroethers, prepared in situ from vinyl ethers 1 and arenesulfenyl chlorides 2) to give the 2-alkoxy-3-arylthioalkyl ketone derivatives 6 in the presence of a Lewis acid.
Trends in alkyl substituent effects on nucleophilic reactions of carbonyl compounds: Gas phase reactions between ammonia and R1R2COCH3+ oxonium ionsElectronic supplementary information (ESI) available: proton affinities, geometries and energies of optimised structures, structures of the stationary points and a plot of experimental and RRKM ln(kae/ksub) against a-stabilisation constants. See http://www.rsc.org/suppdata/ob/b2/b209955c/
作者:Lihn Bache-Andreassen、Einar Uggerud
DOI:10.1039/b209955c
日期:2003.2.11
The reactivity of carbonyl substituted methyl oxonium ions (R1R2COCH3+) towards ammonia has been investigated using an FT-ICR mass spectrometer and ab initio calculations. The monosubstituted ions (R1 = H; R2 = H, CH3, C2H5 and i-C3H7) show different reaction patterns with variable degree of: (1) nucleophilic substitution, (2) addition-elimination and (3) proton transfer, when reacted with ammonia
Commercially available liquid enol ethers and acetates as gaseous alkyne equivalents in cationic Rh(I)/BINAP-catalyzed chemo- and regioselective formal cross-alkyne cyclotrimerizations
作者:Hiromi Hara、Masao Hirano、Ken Tanaka
DOI:10.1016/j.tet.2009.02.047
日期:2009.6
A cationicrhodium(I)/BINAPcomplex catalyzes partial intramolecular [2+2+2] cycloadditions of 1,6- and 1,7-diynes with enol ethers or a ketene acetal giving substituted benzenes in good yields. The same catalyst also catalyzes complete intermolecular [2+2+2] cycloadditions of two different monoynes with enol acetates giving tri- and tetrasubstituted benzenes in good yields with complete regioselectivity