Generation of diverse isoquinoline N-oxides in an aqueous system

4-Halo isoquinoline N-oxides could be synthesized efficiently via the electrophilic cyclization of 2-alkynylbenzaldoximes, involving the in situ generation of the halonium ion in water. The one-pot cyclization-Suzuki reaction in an aqueous system afforded the functionalized isoquinoline N-oxides in good yields.