Rhodium‐Catalyzed Intramolecular Cyclization of Naphthol‐ or Phenol‐Linked 1,6‐Enynes Through the Cleavage and Formation of sp2 CO Bonds

Put a ring on it: A cationic rhodium(I)/binap complex catalyzes the intramolecular cyclization reactions of naphthol- or phenol-linked 1,6-enynes to produce vinylnaphtho- or vinylbenzofurans and vinylnaphtho- or vinylbenzopyrans through the cleavage and formation of sp2 CO bonds. Mechanistic studies imply that the present cyclization reactions proceed through β-oxygen elimination from cationic rhodacycle intermediates.