Synthesis of acenaphthylene-fused heteroarenes and polyoxygenated benzo[j]fluoranthenes via a Pd-catalyzed Suzuki-Miyaura/C-H arylation cascade

YENCE M., Ahmadli D., Surmeli D., Karacaoglu U. M., Pal S., TÜRKMEN Y. E.

BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY, cilt.20, ss.3290-3298, 2024 (SCI-Expanded, Scopus)

Özet

Acenaphthylene-fused heteroarenes with a variety of five- and six-membered heterocycles such as thiophene, furan, benzofuran, pyrazole, pyridine and pyrimidine were synthesized via an efficient Pd-catalyzed reaction cascade in good to high yields (45-90%). This cascade involves an initial Suzuki-Miyaura cross-coupling reaction between 1,8-dihalonaphthalenes and heteroarylboronic acids or esters, followed by an intramolecular C-H arylation under the same conditions to yield the final heterocyclic fluoranthene analogues. The method was further employed to access polyoxygenated benzo[j]fluoranthenes, which are all structurally relevant to benzo[j]fluoranthene-based fungal natural products. The effectiveness of our strategy was demonstrated via a concise, four-step synthesis of the tetramethoxybenzo[j]fluoranthene derivative 18 , which represents a formal total synthesis of the fungal natural product bulgarein.