Fe‐Catalyzed Intramolecular Cross‐Dehydrogenative Arylation (CDA), Efficient Synthesis of 1‐Arylnaphthalenes and 4‐Arylcoumarins

Direct cross‐dehydrogenative coupling of different inert C−H bonds is the most straightforward and environmentally benign method to construct C−C bonds. In this paper, we developed an iron‐catalyzed intramolecular cross‐dehydrogenative arylation (CDA) between benzylic C(sp3)H bond and aromatic C(sp2)H bond. From the readily available linear substrates, 1‐arylnaphthalenes and 4‐arylcoumarins can be quickly constructed with moderate to good yield (18 examples, up to 73 % yield) in one step. Both symmetrical and unsymmetrical substrates with different functional groups could tolerate this system well to form the anticipated products. A radical initiated dehydrogenative cyclization‐dehydrogenation tandem process was proposed.