Relay Rhodium(I)/Acid Catalysis for Rapid Access to Benzo‐2H‐Pyrans and Benzofurans

Abstract Relay rhodium(I)/Brønsted acid catalysis for tandem arylation−cyclization reaction was developed. Chemodivergent syntheses of benzo‐2 H ‐pyrans and benzofurans from propargyl alcohols and ortho ‐hydroxylated arylboronic acids were achieved under this relay catalysis system. An ortho ‐hydroxy effect on changing the chemoselectivity and reactivity was observed. magnified image