PIDA/I2-Mediated α- and β-C(sp3)–H Bond Dual Functionalization of Tertiary Amines
摘要:
The alpha,beta-C(sp(3))-H bond dual functionalization of tertiary amines is still a challenging task for both organic and medicinal chemists. Herein a direct, mild, metal-free, and site-specific method mediated by PIDA/I-2 was developed for alpha,beta-C(sp(3))-H bond dual functionalization of tertiary amines, and this method can provide facile access to alpha-keto lactams or rarely studied alpha,alpha-diiodo lactams. Moreover, this method was used for the effective syntheses of three natural products [obscurumine C (13), obscurumine O (17), and strychnocarpine (18)] and direct preparation of mimics of the in vivo metabolites of two FDA-approved drugs (imatinib and donepezil) in 36-60% overall yield. The method represents a promising protocol for the late-stage alpha,beta-C(sp(3))-H bond oxidative dual functionalization of tertiary amine-containing drugs and complex natural products.
Complementation of Biotransformations with Chemical C–H Oxidation: Copper-Catalyzed Oxidation of Tertiary Amines in Complex Pharmaceuticals
作者:Julien Genovino、Stephan Lütz、Dalibor Sames、B. Barry Touré
DOI:10.1021/ja405471h
日期:2013.8.21
The isolation, quantitation, and characterization of drug metabolites in biological fluids remain challenging. Rapid access to oxidized drugs could facilitate metabolite identification and enable early pharmacology and toxicity studies. Herein, we compared biotransformations to classical and new chemical C-H oxidation methods using oxcarbazepine, naproxen, and an early compound hit (phthalazine 1). These studies illustrated the low preparative efficacy of biotransformations and the inability of chemical methods to oxidize complex pharmaceuticals. We also disclose an aerobic catalytic protocole (CuI/air) to oxidize tertiary amines and benzylic CH's in drugs. The reaction tolerates a broad range of functionalities and displays a high level of chemoselectivity, which is not generally explained by the strength of the C-H bonds but by the individual structural chemotype. This study represents a first step toward establishing a chemical toolkit (chemotransformations) that can selectively oxidize C-H bonds in complex pharmaceuticals and rapidly deliver drug metabolites.