1: 4-trifluoromethylsulfonyloxy-2H-chromene With potassium carbonate; bis(dibenzylideneacetone)-palladium(0) in benzene 0.5 h; 2: 3,4,5-trimethoxyphenylboronic acid in ethanol; benzene Heating;

copper(l) iodide; tetrakis(triphenylphosphine) palladium(0); lithium chloride in 1,4-dioxane Stille coupling; Heating;