Diastereo- and regioselective intramolecular heck reaction of alpha-amino alcohol derivatives for the synthesis of enantiomerically pure isoquinolines and benzazepines at ambient and high pressure
Tietze, L.F.; Burkhardt, O.; Henrich, M.
Liebigs Annalen-Recueil 1997(7): 1407-1413
1997
Accession: 008462268
Alkylation and acylation of the alkenes 9b, c and 10a, b, which are easily prepared from the corresponding alpha-amino alcohols, with 2-halobenzyl and 2-halobenzoyl halides respectively, gives 11-15. These compounds cyclize with excellent diastereo- and regioselectivity to the enantiomerically pure N-heterocycles 18-20 in an intramolecular Heck reaction using 5 mol-% of Pd(OAc)-2 in the presence of PPh-3, TPAB and KOAc. Under the same conditions substrate 17 leads to the enantiomerically pure benzazepine 24. The reaction of the bromoarene derivatives 14-15 must be performed under high pressure to give good results.