AZOBRIDGES FROM AZINES .17. INTRAMOLECULAR AND INTERMOLECULAR [3-CYCLOADDITION BETWEEN NONSTABILIZED AZOMETHINEIMINES AND ALKENES(2])

Azo compounds 1 and 3 containing a CC-double bond in a parallel but di stant position are quatemized by Me(3)OBF(4) to 1,MeBF(4) and 3,MeBF(4 ), whereas MeI produces the cage compounds 2,HX and 4,HX. These [3+2] cycloadducts also are quantitatively formed from 1,MeBF(4) and 3,MeBF( 4) with catalytic amounts of azo compounds. Intermolecular [3+2] cyclo additions occur with a mixture of DBH (5) or DBO (8), Mel and a variet y of alkenes (--> HI) salts of (6, 7, 9 - 12). The intermediate azomet hineimines, if stabilized by a fluorenylidene group, can be isolated ( 20, 22, 24), but not, however. in the presence of a close parallel CC- bond (25 --> 26).