A novel resin-bound CF 3-containing building block: application to the solid-phase synthesis of CF 3-containing acrylates and 4-isoxazolecarboxylates

Abstract

A novel resin-bound CF 3-containing building block ( 3) was prepared. Stereospecific Suzuki cross-coupling of compound 3 with a variety of aryl boronic acids gave the corresponding resin-bound coupling products ( 4), which can be cleaved with sodium methoxide to afford methyl ( E)-3-aryl-4,4,4-trifluoro-2-butenoate ( 5). 1,3-Dipolar cycloaddition of compound 3 with aryl nitrile oxides followed by cleavage with TFA led to methyl 3-aryl-5-trifluoromethyl-4-isoxazolecarboxylate regioselectively, which was determined by 19 F NMR analysis.