Synthesis of 1-borylisoindoles via palladium-catalyzed dehydrogenation/C-H borylation of isoindolines.

1-Boryl- and 1,3-diborylisoindoles were synthesized by the palladium-catalyzed reaction of isoindolines with pinacolborane via sequential dehydrogenation and C-H borylation. Selective formation of the borylated isoindoles was achieved using Pd(dba)(2)/Me(2)S as the catalyst, in which Me(2)S suppressed the formation of 1-boryl-4,5,6,7-tetrahydroisoindoles. Diborylisoindole was cross-coupled with iodobenzene, giving 1,3-diphenylisoindole in high yield.