Visible-light-induced photocatalytic intermolecular cyclization for synthesis of 2,2-diarylchromanes

The photocatalytic cyclization of salicylaldehydes with 1,1-diarylalkenes for the synthesis of 2,2-diarylchromanes has been developed. The catalytic amount of Ir photocatalyst proceeds the cyclization to give the various 2,2-disubtitued chromanes under irradiation with blue LEDs. The obtained 2,2-diarylchromanes exhibit noticeable free-radical-scavenging activities, which have been largely unexplored. Notably, the chromane can convert to 2,2-diaryl-2H-naphtho[1,2- b ]pyran bearing strong electron withdrawing groups, which are found in various photochromic materials. Thus, the present reaction constitutes a promising tool for the synthesis of functional materials and biologically active compounds. • Visible-light-induced photocatalytic intermolecular cyclization for synthesis of 2,2-diarylchromanes has been developed. • The catalytic amount of Ir photocatalyst proceeds the cyclization to give the various electron-deficient 2,2-disubtitued chromanes under irradiation with blue LEDs. • ·The 2,2-diarylchromanes exhibit noticeable free-radical-scavenging activities. • The chromane can convert to electron-deficient 2,2-diaryl-2 H -naphtho[1,2- b ]pyran, which are found in various photochromic materials.