One-pot, three-component, domino Heck-aza-Michael approach to libraries of functionalized 1,1-dioxido-1,2-benzisothiazoline-3-acetic acids.

A sequential three-component synthesis of functionalized benzisothiazoline-3-acetic acid 1,1-dioxides utilizing a domino Heck-aza-Michael pathway is reported. This one-pot procedure rapidly assembles functionalized benzylsulfonamides, which undergo a palladium-catalyzed, domino, Heck-aza-Michael transformation in an experimentally straightforward manner. This attractive protocol has been utilized to synthesize three combinatorial sublibraries (I-III) comprising a total of 95 compounds in high purities (> or =95% for 75 compounds), yield and quantities.