Differentially Protected Benzenediboronic Acids:  Divalent Cross-Coupling Modules for the Efficient Synthesis of Boron-Substituted Oligoarenes

On the basis of the boron-masking strategy, new divalent cross-coupling modules have been designed for the efficient synthesis of boron-substituted oligoarenes. The modules, i.e., monoprotected o-, m-, and p-benzenediboronic acid derivatives, undergo highly selective Suzuki−Miyaura coupling with sp² iodides, bromides, chlorides, and triflates, affording coupling products in which the protected boronyl groups are left intact.