Synthesis of dihydrophenanthridines by a sequence of Ugi-4CR and palladium- catalyzed intramolecular C-H functionalization

• Florence Bonnaterre,
• Michèle Bois-Choussy and
• Jieping Zhu

Beilstein J. Org. Chem. 2008, 4, No. 10, doi:10.3762/bjoc.4.10

• intramolecular C-H functionalization of these adducts under ligandless conditions provided the functionalized dihydrophenanthridines (1). Conclusion Highly functionalized dihydrophenanthridines are synthesized in only two steps from readily accessible starting materials in good to excellent overall yields

• a key intramolecular C-H functionalization reaction [13][14]. As a continuation of this research program, we were interested in the synthesis of dihydrophenanthridines 1 by combined use of Ugi-4CR and a palladium-catalyzed direct CH-arylation process. The synthetic sequence we envisioned is shown in