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1. Oxidative Amide Coupling from Functionally Diverse Alcohols and Amines Using Aerobic Copper/Nitroxyl Catalysis

   https://doi.org/10.1002/ange.201906130  

   Piszel, Paige E. ; Vasilopoulos, Aristidis ; Stahl, Shannon S. ( July 2019 , Angewandte Chemie)

   The aerobic Cu/ABNO catalyzed oxidative coupling of alcohols and amines is highlighted in the synthesis of amide bonds in diverse drug‐like molecules (ABNO=9‐azabicyclo[3.3.1]nonaneN‐oxyl). The robust method leverages the privileged reactivity of alcohols bearing electronegative hetero‐ atoms (O, F, N, Cl) in the β‐position. The reaction tolerates over 20 unique functional groups and is demonstrated on a 15 mmol scale under air. Steric constraints of the catalyst allow for chemoselective amidation of primary amines in the presence of secondary amines. All catalyst components are commercially available, and the reaction proceeds under mild conditions with retention of stereocenters in both reaction partners, while producing only water as a by‐product.

    

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2. Oxidative Amide Coupling from Functionally Diverse Alcohols and Amines Using Aerobic Copper/Nitroxyl Catalysis

   https://doi.org/10.1002/anie.201906130  

   Piszel, Paige E. ; Vasilopoulos, Aristidis ; Stahl, Shannon S. ( July 2019 , Angewandte Chemie International Edition)

   The aerobic Cu/ABNO catalyzed oxidative coupling of alcohols and amines is highlighted in the synthesis of amide bonds in diverse drug‐like molecules (ABNO=9‐azabicyclo[3.3.1]nonaneN‐oxyl). The robust method leverages the privileged reactivity of alcohols bearing electronegative hetero‐ atoms (O, F, N, Cl) in the β‐position. The reaction tolerates over 20 unique functional groups and is demonstrated on a 15 mmol scale under air. Steric constraints of the catalyst allow for chemoselective amidation of primary amines in the presence of secondary amines. All catalyst components are commercially available, and the reaction proceeds under mild conditions with retention of stereocenters in both reaction partners, while producing only water as a by‐product.

    

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3. Concise synthesis of 2,3-disubstituted quinoline derivatives via ruthenium-catalyzed three-component deaminative coupling reaction of anilines, aldehydes and amines

   https://doi.org/10.1039/d3ob00348e  

   Shakenov, Aldiyar ; Gnyawali, Krishna Prasad ; Yi, Chae S. ( May 2023 , Organic & Biomolecular Chemistry)

   The Ru–H complex (PCy 3 ) 2 (CO)RuHCl (1) was found to be a highly effective catalyst for the three-component deaminative coupling reaction of anilines with aldehydes and allylamines to form 2,3-disubstituted quinoline products. The analogous coupling reaction of anilines with aldehydes and cyclic enamines led to the selective formation of the tricyclic quinoline derivatives. The reaction profile study showed that the imine is initially formed from the dehydrative coupling of aniline and aldehyde, and it undergoes the deaminative coupling and annulation reaction with amine substrate to form the quinoline product. The catalytic coupling method provides a step-efficient synthesis of 2,3-disubstituted quinoline derivatives without employing any reactive reagents or forming wasteful byproducts. 

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4. Selective Functionalization of Aliphatic Amines via Myoglobin-Catalyzed Carbene N–H Insertion

   https://doi.org/10.1055/s-0039-1690007  

   Steck, Viktoria ; Sreenilayam, Gopeekrishnan ; Fasan, Rudi ( January 2020 , Synlett)

   Engineered myoglobins have recently gained attention for their ability to catalyze a variety of abiological carbene transfer reactions including the functionalization of amines via carbene insertion into N–H bonds. However, the scope of myoglobin and other hemoprotein-based biocatalysts in the context of this transformation has been largely limited to aniline derivatives as the amine substrates and ethyl diazoacetate as the carbene donor reagent. In this report, we describe the development of an engineered myoglobin-based catalyst that is useful for promoting carbene N–H insertion reactions across a broad range of substituted benzylamines and α-diazo acetates with high efficiency (82–99% conversion), elevated catalytic turnovers (up to 7,000), and excellent chemoselectivity for the desired single insertion product (up to 99%). The scope of this transformation could be extended to cyclic aliphatic amines. These studies expand the biocatalytic toolbox available for the selective formation of C–N bonds, which are ubiquitous in many natural and synthetic bioactive compounds. 

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5. Catalytic C(sp 3 )−H Arylation of Free Primary Amines with an exo Directing Group Generated In Situ

   https://doi.org/10.1002/ange.201604268  

   Xu, Yan ; Young, Michael C. ; Wang, Chengpeng ; Magness, David M. ; Dong, Guangbin ( June 2016 , Angewandte Chemie)

   Herein, we report the palladium‐catalyzed direct arylation of unactivated aliphatic C−H bonds in free primary amines. This method takes advantage of anexo‐imine‐type directing group (DG) that can be generated and removed in situ. A range of unprotected aliphatic amines are suitable substrates, undergoing site‐selective arylation at the γ‐position. Methyl as well as cyclic and acyclic methylene groups can be activated. Furthermore, when aniline‐derived substrates were used, preliminary success with δ‐C−H arylation was achieved. The feasibility of using the DG component in a catalytic fashion was also demonstrated.

    

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