Abstract
Lewis acid catalyzed reactions of N-(4-hydroxy-4,4-diarylbut-2-ynyl)-4-methyl-N-prop-2-ynylbenzene-sulfonamides or 1,1-diphenyl-4-prop-2-ynyloxybut-2-yn-1-ol (1,6-diynes) 1 and N-allyl-N-(4-hydroxy-4,4-diarylbut-2-ynyl)-4-methylbenzenesulfonamides (1,6-enynes) 2 with vinylidenecyclopropanes 3 selectively produce polycyclic compounds 4, 5 and 10 as well as isopropylidene-3,3-diarylcyclobut-1-enyl-methyl derivatives 6 or 7 in good to high yields depending on the substituents on the benzene ring of 3 under mild conditions. An interesting PtCl2-catalyzed cyclization of 6 and a Cu-(OAc)(2)center dot H2O catalyzed Eglinton coupling reaction of 5 and 10 to produce the corresponding 5-isopropylidenc-6-methyl-1-(toluene-4-sulfonyl)-7-vinyl-1,2,3,4,5,8-hexahydroazocine derivatives 8 and the coupling products 9 and 11 in good yields have been disclosed, respectively. Plausible mechanisms of these processes have been proposed that belong to a cascade rearrangement followed by the Friedel-Crafts reaction, an intramolecular proton transferring and a cyclization reaction.