42365-50-4Relevant academic research and scientific papers
Assembly of two new hybrid chloride materials with potential NLO properties: Structure elucidation, empirical and computational studies
Issaoui, Noureddine,Jomaa, Ikram,Marouani, Houda,Roisnel, Thierry
, (2022/01/26)
This paper deals with the crystal structure of two new non-centrosymmetric hybrid compounds obtained from an aqueous solution by slow evaporation method and characterized by various techniques mainly single-crystal X-ray diffraction. In the atomic arrangement of 2-methylbenzylammonium chloride (1), the organic cations and the chloride anions are linked to each other via N–H…Cl hydrogen bonds; organic cations in zigzag distribution along b-axis in z = 0 and z = ? are also close enough to enable a C–H…π interaction to occur. In 3-methylbenzylammonium chloride (2), the organic cations are linked together by C–H…π interactions and through N–H…Cl and C–H…Cl hydrogen bonds to form a two-dimensional network. To support experimental results, DFT calculations have been accomplished via the B3LYP method and 6-311++G(d,p) basis set on molecular geometry, vibrational, and electronic properties. The non-covalent interactions were studied quantitatively using the Hirshfeld surfaces (HS) associated with 2D fingerprint plots. The NLO properties have been also investigated by DFT and compared to the urea reference.
Hydrosilylative reduction of primary amides to primary amines catalyzed by a terminal [Ni-OH] complex
Bera, Jitendra K.,Pandey, Pragati
supporting information, p. 9204 - 9207 (2021/09/20)
A terminal [Ni-OH] complex1, supported by triflamide-functionalized NHC ligands, catalyzes the hydrosilylative reduction of a range of primary amides into primary amines in good to excellent yields under base-free conditions with key functional group tolerance. Catalyst1is also effective for the reduction of a variety of tertiary and secondary amides. In contrast to literature reports, the reactivity of1towards amide reduction follows an inverse trend,i.e., 1° amide > 3° amide > 2° amide. The reaction does not follow a usual dehydration pathway.
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.
Transition metal-free catalytic reduction of primary amides using an abnormal NHC based potassium complex: Integrating nucleophilicity with Lewis acidic activation
Bhunia, Mrinal,Sahoo, Sumeet Ranjan,Das, Arpan,Ahmed, Jasimuddin,Sreejyothi,Mandal, Swadhin K.
, p. 1848 - 1854 (2020/03/03)
An abnormal N-heterocyclic carbene (aNHC) based potassium complex was used as a transition metal-free catalyst for reduction of primary amides to corresponding primary amines under ambient conditions. Only 2 mol% loading of the catalyst exhibits a broad substrate scope including aromatic, aliphatic and heterocyclic primary amides with excellent functional group tolerance. This method was applicable for reduction of chiral amides and utilized for the synthesis of pharmaceutically valuable precursors on a gram scale. During mechanistic investigation, several intermediates were isolated and characterized through spectroscopic techniques and one of the catalytic intermediates was characterized through single-crystal XRD. A well-defined catalyst and isolable intermediate along with several stoichiometric experiments, in situ NMR experiments and the DFT study helped us to sketch the mechanistic pathway for this reduction process unravelling the dual role of the catalyst involving nucleophilic activation by aNHC along with Lewis acidic activation by K ions.
Benzimidazole fragment containing Mn-complex catalyzed hydrosilylation of ketones and nitriles
Ganguli, Kasturi,Mandal, Adarsha,Sarkar, Bidisha,Kundu, Sabuj
, (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.
Silicon hydrogenation reaction method of organic boron and inorganic alkali catalysis amide (by machine translation)
-
Paragraph 0134-0140; 0158-0161, (2020/08/18)
The method is characterized in that organic boron and inorganic bases are used as catalysts, silane is used as a reducing agent, primary amide is reduced to primary amine or dehydration dinitrile, the secondary amide is reduced to a secondary amine or aldimine, and the tertiary amide is reduced to tertiary amine. The method has the advantages of simple operation, mild reaction conditions, wide substrate universality, good functional group compatibility and the like, and has the characteristics of good stability, cheap and accessible catalyst, simple and convenient operation, high practicality and the like. (by machine translation)
Primary amides to amines or nitriles: A dual role by a single catalyst
Das, Hari S.,Das, Shyamal,Dey, Kartick,Singh, Bhagat,Haridasan, Rahul,Das, Arpan,Ahmed, Jasimuddin,Mandal, Swadhin K.
supporting information, p. 11868 - 11871 (2019/10/11)
We report a manganese-catalyzed hydrosilylative reduction of various primary amides to amines (25 examples). On simple modification of the reaction conditions such as in the presence of a catalytic amount of secondary amide, the same catalyst can transform the primary amides into intermediate nitrile compounds (16 examples) in excellent yields. This is the first example where such a controlled catalytic transformation of primary amides to amines or nitriles with a single catalyst has been demonstrated.
A BEt3-Base catalyst for amide reduction with silane
Yao, Wubing,Fang, Huaquan,He, Qiaoxing,Peng, Dongjie,Liu, Guixia,Huang, Zheng
, (2019/05/22)
Reported herein is the development of a simple but practical catalytic system for the selective reduction of amides with hydrosilane or hydrosiloxane. Low-cost and readily available triethylborane (1.0 M in THF), in combination with a catalytic amount of an alkali metal base, was found to catalyze the reduction of all three amide classes (tertiary, secondary, and primary amides) to form amines under mild conditions. In addition, the selective transformation of secondary amides to aldimines and primary amides to nitriles can also be achieved by using a proper combination of BEt3 and base. The scope of these BEt3-base-catalyzed amide hydrosilylation reactions has been explored in depth. Preliminary results of mechanistic studies suggest a modified Piers' silane Si-H···B activation mode wherein the hydride abstraction by BEt3 is promoted by the coordination of an alkoxide or hydroxide anion to the Si center.
A BEt3-Base Catalyst for Amide Reduction with Silane
Yao, Wubing,Fang, Huaquan,He, Qiaoxing,Peng, Dongjie,Liu, Guixia,Huang, Zheng
, p. 6084 - 6093 (2019/05/24)
Reported herein is the development of a simple but practical catalytic system for the selective reduction of amides with hydrosilane or hydrosiloxane. Low-cost and readily available triethylborane (1.0 M in THF), in combination with a catalytic amount of an alkali metal base, was found to catalyze the reduction of all three amide classes (tertiary, secondary, and primary amides) to form amines under mild conditions. In addition, the selective transformation of secondary amides to aldimines and primary amides to nitriles can also be achieved by using a proper combination of BEt3 and base. The scope of these BEt3-base-catalyzed amide hydrosilylation reactions has been explored in depth. Preliminary results of mechanistic studies suggest a modified Piers' silane Si-H···B activation mode wherein the hydride abstraction by BEt3 is promoted by the coordination of an alkoxide or hydroxide anion to the Si center.
Hydrosilane Reduction of Nitriles to Primary Amines by Cobalt-Isocyanide Catalysts
Sanagawa, Atsushi,Nagashima, Hideo
supporting information, p. 287 - 291 (2019/01/10)
Reduction of nitriles to silylated primary amines was achieved by combination of 1,1,3,3-tetramethyldisiloxane (TMDS) as the hydrosilane and a catalytic amount of Co(OPIV)2 (PIV = COtBu) associated with isocyanide ligands. The resulting silylated amines were subjected to acid hydrolysis or treatment with acid chlorides to give the corresponding primary amines or imides in good yields. One-pot synthesis of primary amides to primary amines with hydrosilanes was also achieved by iron-cobalt dual catalyst systems.
