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1. Synthesis of Symmetric and Unsymmetric Secondary Amines from the Ligand Promoted Ruthenium Catalyzed Deaminative Coupling Reaction of Primary Amines

   Arachchige, P. T. ; Hanbin Lee, H. ; Chae S. Yi, C. S. ( January 2018 , Journal of organic chemistry)

   The catalytic system generated in-situ from the tetranuclear Ru–H complex with a catechol ligand (1/L1) was found to be effective for the direct deaminative coupling of two primary amines to form secondary amines. The catalyst 1/L1 was highly chemoselective for promoting the coupling of two different primary amines to afford unsymmetric secondary amines. The analogous coupling of aniline with primary amines formed aryl-substituted secondary amines. The treatment of aniline-d7 with 4-methoxybenzylamine led to the coupling product with significant deuterium incorporation on CH2 (18% D). The most pronounced carbon isotope effect was observed on the -carbon of the product isolated from the coupling reaction of 4-methoxybenzylamine (C(1) = 1.015(2)). Hammett plot was constructed from measuring the rates of the coupling reaction of 4-methoxyaniline with a series of para-substituted benzylamines 4-X-C6H4CH2NH2 (X = OMe, Me, H, F, CF3). ( = -0.79 ± 0.1). A plausible mechanistic scheme has been proposed for the coupling reaction on the basis of these results. The catalytic coupling method provides an operationally simple and chemoselective synthesis of secondary amine products without using any reactive reagents or forming wasteful byproducts. 

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2. New particle formation from sulfuric acid and amines: Comparison of monomethylamine, dimethylamine, and trimethylamine: Particle Formation From Different Amines

   https://doi.org/10.1002/2017JD026501  

   Olenius, Tinja ; Halonen, Roope ; Kurtén, Theo ; Henschel, Henning ; Kupiainen-Määttä, Oona ; Ortega, Ismael K. ; Jen, Coty N. ; Vehkamäki, Hanna ; Riipinen, Ilona ( July 2017 , Journal of Geophysical Research: Atmospheres)
3. 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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4. Knudsen cell studies of the uptake of gaseous ammonia and amines onto C3–C7 solid dicarboxylic acids

   https://doi.org/10.1039/C7CP05252A  

   Fairhurst, Michelle C. ; Ezell, Michael J. ; Finlayson-Pitts, Barbara J. ( January 2017 , Phys. Chem. Chem. Phys.)

   While atmospheric particles affect health, visibility and climate, the details governing their formation and growth are poorly understood on a molecular level. A simple model system for understanding the interactions between the gas and particle phases is the reaction of bases with acids, both of which are common constituents of atmospheric particles. In the present study, uptake coefficients for the reactions of gas phase ammonia, methylamine, ethylamine, dimethylamine and trimethylamine with a series of solid dicarboxylic acids (diacids) were measured at 296 ± 1 K using a Knudsen cell interfaced to a quadrupole mass spectrometer. The uptake coefficients ( γ ) for a given amine follow an odd–even trend in carbon number of the diacid, and are larger for the odd carbon diacids. Values range from γ = 0.4 for ethylamine on malonic acid (C3) to less than ∼10 −6 for ammonia and all amines on adipic (C6) and pimelic (C7) acids. Basicity or structure of the amines/ammonia alone do not explain the effect of the base on uptake. The crystal structures of the diacids also play a key role, which is especially evident for malonic acid (C3). Evaporation of aqueous mixtures of amines/ammonia with odd carbon diacids show the formation of ionic liquids (ILs) or in some cases, metastable ILs that revert back to a stable solid salt upon complete evaporation of water. The trends with amine and diacid structure provide insight into the mechanisms of uptake and molecular interactions that control it, including the formation of ionic liquid layers in some cases. The diversity in the kinetics and mechanisms involved in this relatively simple model system illustrate the challenges in accurately representing such processes in atmospheric models. 

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5. Enantio- and Diastereoselective Synthesis of Homoallylic α-Trifluoromethyl Amines by Catalytic Hydroalkylation of Dienes

   https://doi.org/10.1021/acs.orglett.0c00342  

   Onyeagusi, Chibueze I. ; Shao, Xinxin ; Malcolmson, Steven J. ( February 2020 , Organic Letters)