459-19-8Relevant articles and documents
Phosphine-Free Manganese Catalyst Enables Selective Transfer Hydrogenation of Nitriles to Primary and Secondary Amines Using Ammonia-Borane
Sarkar, Koushik,Das, Kuhali,Kundu, Abhishek,Adhikari, Debashis,Maji, Biplab
, p. 2786 - 2794 (2021/03/03)
Herein we report the synthesis of primary and secondary amines by nitrile hydrogenation, employing a borrowing hydrogenation strategy. A class of phosphine-free manganese(I) complexes bearing sulfur side arms catalyzed the reaction under mild reaction conditions, where ammonia-borane is used as the source of hydrogen. The synthetic protocol is chemodivergent, as the final product is either primary or secondary amine, which can be controlled by changing the catalyst structure and the polarity of the reaction medium. The significant advantage of this method is that the protocol operates without externally added base or other additives as well as obviates the use of high-pressure dihydrogen gas required for other nitrile hydrogenation reactions. Utilizing this method, a wide variety of primary and symmetric and asymmetric secondary amines were synthesized in high yields. A mechanistic study involving kinetic experiments and high-level DFT computations revealed that both outer-sphere dehydrogenation and inner-sphere hydrogenation were predominantly operative in the catalytic cycle.
Benzimidazole fragment containing Mn-complex catalyzed hydrosilylation of ketones and nitriles
Ganguli, Kasturi,Mandal, Adarsha,Sarkar, Bidisha,Kundu, Sabuj
supporting information, (2020/08/13)
The synthesis of a new bidentate (NN)–Mn(I) complex is reported and its catalytic activity towards the reduction of ketones and nitriles is studied. On comparing the reactivity of various other Mn(I) complexes supported by benzimidazole ligand, it was observed that the Mn(I) complexes bearing 6-methylpyridine and benzimidazole fragments exhibited the highest catalytic activity towards monohydrosilylation of ketones and dihydrosilylation of nitriles. Using this protocol, a wide range of ketones were selectively reduced to the corresponding silyl ethers. In case of unsaturated ketones, the chemoselective reduction of carbonyl group over olefinic bonds was observed. Additionally, selective dihydrosilylation of several nitriles were also achieved using this complex. Mechanistic investigations with radical scavengers suggested the involvement of radical species during the catalytic reaction. Stoichiometric reaction of the Mn(I) complex with phenylsilane revealed the formation of a new Mn(I) complex.
Regio- and stereoselective hydroamination of alkynes using an ammonia surrogate: Synthesis of N -Silylenamines as reactive synthons
Lui, Erica K. J.,Brandt, Jason W.,Schafer, Laurel L.
supporting information, p. 4973 - 4976 (2018/04/24)
An anti-Markovnikov selective hydroamination of alkynes with N-silylamines to afford N-silylenamines is reported. The reaction is catalyzed by a bis(amidate)bis(amido)Ti(IV) catalyst and is compatible with a variety of terminal and internal alkynes. Stoichiometric mechanistic studies were also performed. This method easily affords interesting N-silylenamine synthons in good to excellent yields and the easily removable silyl protecting group enables the catalytic synthesis of primary amines.
Selective Hydrogenation of Nitriles to Primary Amines Catalyzed by a Polysilane/SiO2-Supported Palladium Catalyst under Continuous-Flow Conditions
Saito, Yuki,Ishitani, Haruro,Ueno, Masaharu,Kobayashi, Shū
, p. 211 - 215 (2017/04/21)
Hydrogenation of nitriles to primary amines with heterogeneous catalysts under liquid-phase continuous-flow conditions is described. Newly developed polysilane/SiO2-supported Pd was found to be an effective catalyst and various nitriles were converted into primary amine salts in almost quantitative yields under mild reaction conditions. Interestingly, a complex mixture was obtained under batch conditions. Lifetime experiments showed that this catalyst remained active for more than 300 h (TON≥10 000) without loss of selectivity and no metal leaching from the catalyst occurred. By using this continuous-flow hydrogenation, synthesis of venlafaxine, an antidepressant drug, has been accomplished.
Microwave-assisted synthesis of primary amine HX salts from halides and 7 M ammonia in methanol
Saulnier, Mark G.,Zimmermann, Kurt,Struzynski, Charles P.,Sang, Xiaopeng,Velaparthi, Upender,Wittman, Mark,Frennesson, David B.
, p. 397 - 399 (2007/10/03)
The atom economical synthesis of hydrogen halide salts of primary amines, directly from the corresponding halides, avoids the production of significant amounts of secondary amine side products, and requires only evaporation of the solvent to access the products in yields generally greater than 90%. The procedure uses microwave irradiation in 7 M ammonia in methanol (Aldrich) at 130°C from 0.5 to 2.5h and works on a variety of alkyl halides, as well as mesylates and tosylates. Benzylamines are obtained from benzyl halides without significant amounts of the secondary amine side products that result without microwave heating. Direct isolation of even highly volatile primary amines as their hydrogen halide salts makes the method ideal for use in parallel synthesis.
Method of treating nausea and vomiting with certain substituted-phenylalkylamino (and aminoacid) derivatives and other serotonin depleting agents
-
, (2008/06/13)
A method for the treatment of emesis in a mammal, which method comprises administering to said mammal an emesis inhibiting amount of a compound which depletes serotonin in the brain of mammals; among which are compounds having the formula: STR1 wherein, R is selected from hydrogen, loweralkyl, trifluoromethyl, carboxyl, or loweralkoxycarbonyl; R1 and R2 are hydrogen or loweralkyl; Z is trifluoromethyl or halogen; the optical isomers and pharmaceutically acceptable salts thereof; two of the preferred compounds of the invention are fenfluramine and norfenfluramine.
