Intramolecular cocyclisation of 4-azaocta-1,7-dienes, -1-en-7-ynes, -7
-en-1-ynes and -1,7-diynes using 'zirconocene' equivalents affords 3-a
za-8-zirconabicyclo[4.3.0]nonanes, -6-enes, -9-enes or -6,9-dienes. Pr
otonolysis, iodinolysis, or carbonylation of these complexes affords 3
,4-disubstituted piperidines. Exocyclic 1,3-dienes formed from the cou
pling/protonolysis of 4-azaocta-1,7-diynes react with activated dienop
hiles to yield reduced isoquinolines.