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Formation of Novel Photodimers from 4‐Aryl‐1,4‐dihydropyridines
Author(s) -
Hilgeroth Andreas,
Baumeister Ute
Publication year - 2001
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/1521-3765(20011105)7:21<4599::aid-chem4599>3.0.co;2-u
Subject(s) - dimer , irradiation , aryl , chemistry , photochemistry , derivative (finance) , fragmentation (computing) , lambda , crystal structure , solid state , stereochemistry , crystallography , medicinal chemistry , organic chemistry , physics , optics , alkyl , computer science , nuclear physics , financial economics , economics , operating system
N ‐substituted 3‐alkoxycarbonyl‐4‐aryl‐1,4‐dihydropyridines have been photochemically investigated for the first time. In contrast to reports of analogous 3,5‐dialkoxycarbonyl derivatives, they are unreactive in the solid state with shortest distances of potentially reacting double bonds of 6.883(3) Å for one derivative examined by x‐ray crystal structure analysis. Solution irradiation with unfiltered light ( λ ≥270 nm) led to novel diazatetrakishomocubanes in 30–50 % yields. Diazatetrakishomocubanes were also obtained by irradiation with filtered light ( λ >313 nm) besides head‐to‐tail connected syn ‐dimers. The irradiation of the syn ‐dimers with unfiltered light led to centrosymmetric cage dimers accompanied by some dimer fragmentation. Formation of the homocubanes via intermediate biradicals is supported by the available data.