- A versatile domino synthesis affording novel S- and U-shaped terpyridines. Synthesis, properties and crystal structure
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The development of a simple and general method for the preparation of multifunctional terpyridines is described. The treatment of the ketones 1a-g with ternary iminium salts results in the formation of the isomeric terpyridines 6 and 8 (according to a domino reaction). A possible reaction mechanism is discussed. In some cases the isolation of the postulated dihydropyridine intermediates was successful. The isolation of the 1,4-dihydropyridines 5e, 5j, and 5r (donor-substituted) is surprising, because most of the stable dihydropyridines are acceptor-substituted. In several cases the yields of such domino reactions are very high (>80%). Whether S-or U-shaped terpyridines are formed is immediately recognized by NMR spectroscopy. Some special cases (8c, 8e, 6h) were investigated by means of single-crystal X-ray analysis. VCH Verlagsgesellschaft mbH, 1996.
- Keuper, Ralf,Risch, Nikolaus,Floerke, Ulrich,Haupt, Hans-Juergen
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p. 705 - 715
(2007/10/03)
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- Application of iminium salts in the synthesis of fused pyridines. Introduction of substituents using ternary iminium perchlorates
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Ternary iminium perchlorates are used as synthetic equivalents for aliphatic and aromatic aldehydes in a complex one pot reaction, providing an easy access to terpyridines with peripheral substituents. According to the proposed reaction mechanism this is
- Westerwelle,Risch
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p. 1775 - 1778
(2007/10/02)
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- POLYAZA CAVITY SHAPED MOLECULES 13. A VERSATILE NEW TERPYRIDINE SYNTHESIS
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The reaction of morpholine enamines derived from α-pyridyl ketones with aromatic aldehydes leads to the formation of a 1,5-diketone intermediate which in turn provides a 4'-substituted derivative of 2,2',6',2''-terpyridine.
- Hegde, Vidyadhar,Jahng, Yurngdong,Thummel, Randolph P.
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p. 4023 - 4026
(2007/10/02)
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