Abstract: | Readily available alkenylphenols react with allenes under rhodium catalysis to provide valuable 2,2‐disubstituted 2H‐chromenes. The whole process, which involves the cleavage of one C? H bond of the alkenyl moiety and the participation of the allene as a one‐carbon cycloaddition partner, can be considered a simple, versatile, and atom‐economical (5+1) heteroannulation. The reaction tolerates a broad range of substituents both in the alkenylphenol and in the allene, and most probably proceeds through a mechanism involving a rhodium‐catalyzed C? C coupling followed by two sequential pericyclic processes. |