Synthesis of Phenanthro[9,10-b]indolizidin-9-ones, Phenanthro[9,10-b]quinolizidin-9-one, and Related Benzolactams by Pd(OAc)(2)-Catalzed Direct Aromatic Carbonylation

Phenanthro[9,10-b]indolizidin-9-ones, phenanthro[9,10-b]-quinolizidin-9-one, and related benzolactam were synthesized by benzolactam ring formation using Pd(OAc)(2)-catalyzed direct aromatic carbonylation. This also constitutes a formal synthesis of the representative phenanthroindolizidine and -quinolizidine alkaloids (+/-)-tylophorine, (+/-)-antofine, and (+/-)-cryptopleurine. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)