title: Molecular design of organic superbases, azacalix[3](2,6)pyridines: catalysts for 1,2- and 1,4-additions.
abstract: 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 CD(3)CN. These derivatives were shown to be efficient catalysts for 1,4-addition reactions of nitroalkanes or primary alcohols to α,β-unsaturated carbonyl compounds and 1,2-addition reactions of nitroalkanes to aromatic aldehydes.
authors.affiliation: Tsukuba Research Center for Interdisciplinary Materials Science, Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8573, Japan.
authors.forename: Natsuko
authors.initials: N
authors.lastname: Uchida
authors.forename: Junpei
authors.initials: J
authors.lastname: Kuwabara
authors.forename: Ayako
authors.initials: A
authors.lastname: Taketoshi
authors.forename: Takaki
authors.initials: T
authors.lastname: Kanbara