N-Chloro- N-sodio-carbamates as a Practical Amidating Reagent for Scalable and Sustainable Amidation of Aldehydes under Visible Light
Herein, we describe the scalability and sustainability investigations toward the visible light-mediated amidation of aldehydes with N-chloro-N-sodio-carbamates. The practicality credentials of N-chloro-N-sodio-carbamates for their use in multigram scale a
(NHC)Cu-Catalyzed Mild C-H Amidation of (Hetero)arenes with Deprotectable Carbamates: Scope and Mechanistic Studies
Primary arylamines are an important unit broadly found in synthetic, biological, and materials science. Herein we describe the development of a (NHC)Cu system that mediates a direct C-H amidation of (hetero)arenes by using N-chlorocarbamates or their sodio derivatives as the practical amino sources. A facile stoichiometric reaction of reactive copper-aryl intermediates with the amidating reagent led us to isolate key copper arylcarbamate species with the formation of a C-N bond. The use of tBuONa base made this transformation catalytic under mild conditions. The present (NHC)Cu-catalyzed C-H amidation works efficiently and selectively on a large scale over a range of arenes including polyfluorobenzenes, azoles, and quinoline N-oxides. Deprotection of the newly installed carbamate groups such as Boc and Cbz was readily performed to afford the corresponding primary arylamines.
Xie, Weilong,Yoon, Jung Hee,Chang, Sukbok
supporting information
p. 12605 - 12614
(2016/10/07)
Synthesis of 8-Aminoquinolines by Using Carbamate Reagents: Facile Installation and Deprotection of Practical Amidating Groups
Described herein is the development of practical routes to 8-aminoquinolines by using readily installable and easily deprotectable amidating reagents. Two scalable procedures were optimized under RhIII-catalyzed conditions: i) the use of pre-generated chlorocarbamates and ii) a two-step one-pot process that directly employs carbamates. Both approaches are highly convenient for the gram-scale synthesis of 8-aminoquinolines under mild conditions. Facile deprotection of the synthetically versatile amidating groups was achieved under the Pd-catalyzed transfer hydrogenation conditions with simultaneous deoxygenation of quinoline N-oxides, thus yielding 8-aminoquinolines in excellent overall efficiency.
Convenient methods for the direct conversion of imidazolium salts to the corresponding 2-imidazolone or 2-imino imidazole derivatives have been developed. Treatment of the salt with commercial bleach leads to effective oxidation at C2 and the formation of the corresponding imidazolone. Alternatively, treatment of the salt with an N-chloro amide affords the corresponding protected 2-amino derivative in good yield.
Lima, Heather M.,Lovely, Carl J.
supporting information; experimental part
p. 5736 - 5739
(2011/12/05)
Aziridination of C60 with simple amides and catalytic rearrangement of the aziridinofullerenes to azafulleroids
The selective formation of aziridinofullerene and azafulleroid, which are isomers of the fullerene derivatives-introduced N1 unit, is achieved. The ionic aziridination is a very convenient and risk-free procedure compared with the conventional