Concave reagents, 8. Concave pyridines and 1,10‐phenanthrolines with sulfonamide bridgeheads. Increased basicity by 4‐diethylamino substitution of the pyridine unit
Concave reagents, 8. Concave pyridines and 1,10‐phenanthrolines with sulfonamide bridgeheads. Increased basicity by 4‐diethylamino substitution of the pyridine unit
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凹面试剂,8. 凹面吡啶和带有磺酰胺桥头的 1,10-菲咯啉 通过吡啶单元的 4-二乙氨基取代增加碱度。
DOI:
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发表时间:
1991
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影响因子:
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通讯作者:
Michael Müller
中科院分区:
文献类型:
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作者:
U. Lüning;R. Baumstark;Michael Müller
Bimacrocyclic concave pyridinebissulfonamides 2 and concave 1,10-phenanthrolinebissulfonamides 4 have been synthesized by bridging macrocyclic pyridinediamines 12 or 1,10-phenanthrolinediamines 16 with alkylenebis(sulfonyl chloride)s 14. In contrast to concave pyridine- and 1,10-phenanthrolinebislactams 1 and 3, the new compounds 2 and 4 exhibit simpler 1H-NMR spectra and sharper melting points due to the absence of amide conformers; in comparison to 1, the basicities of 2 are decreased by a factor of ca. 100. By introduction of donor substituents into the 4-position of the pyridine ring the basicity loss can be easily compensated. The 4-diethylamino substituent increases the basicity of the concave pyridines 1 and 2 as expected (ca. + 4 pK units). Since no deviations from the expected basicity and reactivity for the amino-substituted concave pyridines 1 and 2 have been found, also in these sterically hindered pyridines, the pyridine nitrogen atom is the centre of basicity and reactivity. – The synthesis of new building blocks is described, i.e. 4-diethylamino-2,6-pyridinedicarbaldehyde (9c), the polyether-based bis(sulfonyl chloride) 14b, the monomacrocyclic diamines 12e–h with a pentaethyleneglycol chain or a 4-diethylamino substituent.