Palladium-Catalyzed C(sp3)-H Arylation of N-Boc Benzylalkylamines via a Deprotonative Cross-Coupling Process

Abstract

Diarylmethylamines are key intermediates and products in the pharmaceutical industry. Herein we disclose a novel method toward the synthesis of these important compounds via C-H functionalization. Presented is a reversible deprotonation of N-Boc benzylalkylamines at the benzylic C-H with in situ arylation by a NiXantPhos-based palladium catalyst (50-93 % yield, 29 examples). The method is also successful with N-Boc-tetrahydroisoquinolines. The advantages of this method are it avoids strong bases, low temperatures, and the need to transmetallate to main group metals for the coupling. Skipping steps! Diarylmethylamines are key intermediates and products in the pharmaceutical industry. A novel method toward the synthesis of these important compounds via C-H functionalization is reported. A reversible deprotonation of N-Boc benzylalkylamines at the benzylic C-H is coupled with in situ arylation with a (NiXantPhos)Pd-based catalyst (50-93 % yield, 29 examples). The advantages of this method are that it avoids strong bases, low temperatures, and the need to transmetallate to main group metals for the coupling.