A facile method employing styrene-type carboxylicesters or amides in the presence of PhICl2 in CH3CN was developed to achieve the synthesis of 6-endo products 3,4-dihydroisocoumarins or 3,4-dihydroisocoumarin-1-imines in good to high yields. This metal-free regioselective intramolecular chlorolactonization process was proposed to involve a PhICl2-mediated oxidative C-O bond formation followed by C-Cl
Divergent Thio/Selenolactonization of Styrene-Type Carboxylic Acids and Amides: Synthesis of Chalcogenated Isobenzofuran-1 (3H)-ones and Isochroman-1-ones
synthesis of isobenzofuran-1(3H)-one and 3,4-dihydroisochroman-1-one derivatives has been realized through the reaction of o-alkenyl benzoic acids/amides with PhICl2 and diphenyl disulfides/diselenides. Depending on the substitution type of the o-alkenyl benzoic acid or amide, this metal-free intramolecular oxychalcogenation approach regioselectively affords isobenzofuran-1(3H)-ones or 3,4-dihydroisochroman-1-ones