作者:Philip B. Kisanga、Palanichamy Ilankumaran、Brandon M. Fetterly、John G. Verkade
DOI:10.1021/jo010228k
日期:2002.5.1
The 1,4-addition of primary alcohols, higher nitroalkanes, and a Schiff's base of an alpha-amino ester to alpha,beta-unsaturated substrates produces the corresponding products in moderate to excellent yields when carried out at -63 to 70 degreesC in the presence of catalytic amounts of the nonionic strong bases P(RNCH2CH2)(3)N (R = Me, i-Pr, i-Bu) in isobutyronitrile. Diastereoselectivity for the anti form of the product is high in the case of the Schiff's base in the absence of lithium ion. These catalysts are easily removed from the product by either column filtration through silica gel or via aqueous workup.
Lunt,E., Tetrahedron, Supplement, 1964, vol. 6, p. 291 - 315
作者:Lunt,E.
DOI:——
日期:——
Molecular Design of Organic Superbases, Azacalix[3](2,6)pyridines: Catalysts for 1,2- and 1,4-Additions
The molecular design, characteristics, and catalytic activity of macrocyclic amino compounds, azacalix[3](2,6)pyridine derivatives, were studied. The introduction of an electron-donating group on the pyridine moiety and bridging amino phenyl group enabled the enhancement of the basicity of azacalix[3](2,6)pyridine up to pK(BH+) = 29.5 in CD3CN. These derivatives were shown to be efficient catalysts for 1,4-addition reactions of nitroalkanes or primary alcohols to alpha,beta-unsaturated carbonyl compounds and 1,2-addition reactions of nitroalkanes to aromatic aldehydes.