Although metal-catalyzed direct arylation reactions of non- or weakly acidic C-H bonds have recently received much attention, chemists have relied heavily on substrates with appropriately placed directing groups to steer reactivity. To date, examples of intermolecular arylation of unactivated C(sp(3))-H bonds in the absence of a directing group remain scarce. We report herein the first general, high-yielding, and scalable method for palladium-catalyzed C(sp(3))-H arylation of simple diarylmethane derivatives with aryl bromides at room temperature. This method facilitates access to a variety of sterically and electronically diverse hetero- and nonheteroaryl-containing triarylmethanes, a class of compounds with various applications and interesting biological activity. Key to the success of this approach is an in situ metalation of the substrate via C-H deprotonation under catalytic cross-coupling conditions, which is referred to as a deprotonative-cross-coupling process (DCCP). Base and catalyst identification were performed by high-throughput experimentation (HTE) and led to a unique base/catalyst combination [KN(SiMe(3))(2)/Pd-NiXantphos] that proved to efficiently promote the room-temperature DCCP of diarylmethanes. Additionally, the DCCP exhibits remarkable chemoselectivity in the presence of substrates that are known to undergo O-, N-, enolate-, and C(sp(2))-H arylation.

Diarylmethanes undergo a base-promoted Pd(II)-catalyzed reaction with bromoarenes to yield triarylmethanes under mild conditions in a chemoselective manner. Surprisingly, only NiXantphos is found to be a suitable ligand for achieving high yields. -(ZHANG, J.; BELLOMO, A.; CREAMER, A. D.; DREHER, S. D.; WALSH*, P. J.; J. Am. Chem. Soc. 134 (2012) 33, 13765-13772, http://dx.doi.org/10.1021/ja3047816 ; Dep. Chem., Univ. Pa., Philadelphia, PA 19104, USA; Eng.) -Mais 08-091

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