Integrated continuous-flow/batch protocol for ortho-selective alkynylation of (hetero)aryl tosylates

Abstract

The ortho-selective alkynylation of polyhalo-substituted (hetero)aryl tosylates was investigated using an integrated continuous-flow/batch protocol. Without the elimination of the tosyloxy group, the regioselective ortho-metalation of the (hetero)aryl tosylates employing n-BuLi and ZnCl2 was successfully achieved in continuous-flow chemistry within 10.92 s (residence time). The Pd-catalyzed Negishi alkynylations of various iodoethynyl (hetero)arenes and the resulting arylzinc species proceeded at room temperature in yields ranging from 51% to 95%. Finally, the synthetic utility of this strategy was validated by the synthesis of benzofuran and pyridofuran derivatives. © 2023 Korean Chemical Society, Seoul & Wiley-VCH GmbH.