On the Reaction of (Vinylimino)phosphoranes and Related Compounds. 20. Syntheses and Properties of Methanocyclodecapyridine Ring Systems

Article abstract of DOI:10.1021/jo00028a040

Novel 2-<(triphenyl- and 2-<(tributylphosphoranylidene)amino>-1,6-methano<10>annulenes (8x, y) and 3-<(triphenyl- and 3-<(tributylphosphoranylidene)amino>-1,6-methanol<10>annulenes (9x, y) were generated by the Staudinger reaction of 2- and 3-azido-1,6-methano<10>annulenes (5 and 6).The compound 8x was inert to α,β-unsaturated ketones, while compounds 8y adn 9y were found to react with α,β-unsaturated ketones in enamine-alkylation process followed by aza-Wittig reaction and dehydrogenation to give 7,12- and 5,10-methanocyclodecapyridines 20a-f and 26a, f, respectively.The reactivity of 8 and 9 as well as the site selectivity of 9 was suggested by their 13C NMR spectra, in which the carbon signals of the nucleophilic center appear at higher field as compared to those of 1,6-methano<10>annulene.Structural properties of 20a-f and 26a, f were remarkable reduction of a ring current and appearance of bond alternation as compared to the parent 1,6-methano<10>annulene (1).The UV spectra exhibiting a prolonged cyclic conjugation are in contrast to their 10? electron analogues, 1,6-methano<10>annulene (1) and quinoline derivatives.