19005-54-0Relevant academic research and scientific papers
Teaching Old Compounds New Tricks: DDQ-Photocatalyzed C?H Amination of Arenes with Carbamates, Urea, and N-Heterocycles
Das, Somnath,Natarajan, Palani,K?nig, Burkhard
, p. 18161 - 18165 (2017)
The C?H amination of benzene derivatives was achieved using DDQ as photocatalyst and BocNH2 as the amine source under aerobic conditions and visible light irradiation. Electron-deficient and electron-rich benzenes react as substrates with moderate to good product yields. The amine scope of the reaction comprises Boc-amine, carbamates, pyrazoles, sulfonimides and urea. Preliminary mechanistic investigations indicate arene oxidation by the triplet of DDQ to radical cations with different electrophilicity and a charge transfer complex between the amine and DDQ as intermediate of the reaction.
Site-selective arene C-H amination via photoredox catalysis
Romero, Nathan A.,Margrey, Kaila A.,Tay, Nicholas E.,Nicewicz, David A.
, p. 1326 - 1330 (2015/10/12)
Over the past several decades, organometallic cross-coupling chemistry has developed into one of the most reliable approaches to assemble complex aromatic compounds from preoxidized starting materials. More recently, transition metal-catalyzed carbon-hydrogen activation has circumvented the need for preoxidized starting materials, but this approach is limited by a lack of practical amination protocols. Here, we present a blueprint for aromatic carbon-hydrogen functionalization via photoredox catalysis and describe the utility of this strategy for arene amination. An organic photoredox-based catalyst system, consisting of an acridinium photooxidant and a nitroxyl radical, promotes site-selective amination of a variety of simple and complex aromatics with heteroaromatic azoles of interest in pharmaceutical research. We also describe the atom-economical use of ammonia to form anilines, without the need for prefunctionalization of the aromatic component.
