A Solution to protodeborylation problem: weak base-promoted direct cross-coupling of naphthalene-1,8-diaminato-substituted arylboron compounds

Direct Suzuki–Miyaura cross-coupling (SMC) of naphthalene-1,8-diaminato (dan)-substituted organoboron reagents, previously requiring the use of a strong base for activation, has been successfully accomplished using a weak base in palladium/copper cocatalysis. This advancement allows for the efficient participation of various perfluoroaryl– and heteroaryl–B(dan) reagents, known for their outstanding resistance to protodeborylation. The formation of an aryl copper species through transmetalation between an aryl–B(dan) and a copper catalyst is pivotal for this smooth transformation. Furthermore, the inherent inertness of the B(dan) moiety arising from its diminished Lewis acidity allowed sequential cross-coupling, where other metallic moieties chemoselectively undergo the reaction, thus leading to the concise, protection-free synthesis of oligoarenes.