Iridium-Catalyzed Tandem Cyclization of Benzoylacetonitriles with Diazo Compounds Leading to Substituted Naphtho[1,8-bc]pyrans by Sequential C-H Functionalization

摘要

The cascade annulation reactions of benzoylacetonitriles with diazo compounds proceed efficiently in the presence of an iridium catalyst to give substituted naphtho[1,8-bc] pyrans by sequential cleavage of C(sp(2))-H/C(sp(3))-H and C(sp(2))-H/O-H bonds. Interestingly, the reactions involving cyclic diazo compounds and open-chain diazo compounds lead to different types of naphtho[1,8-bc] pyrans. Most products are obtained in moderate to good yields with a broad range of substrates.