2032-33-9Relevant academic research and scientific papers
Trimethyl Borate-Catalyzed, Solvent-Free Reductive Amination
Ramachandran, P. Veeraraghavan,Choudhary, Shivani,Singh, Aman
, p. 4274 - 4280 (2021/03/09)
Solvent-free reductive amination of aldehydes and ketones with aliphatic and aromatic amines in high-to-excellent yields has been achieved with sub-stoichiometric trimethyl borate as promoter and ammonia borane as reductant.
Discovery of tert-amine-based RORγt agonists
Qiu, Ruomeng,Yu, Mingcheng,Gong, Juwen,Tian, Jinlong,Huang, Yafei,Wang, Yonghui,Xie, Qiong
, (2021/07/26)
The nuclear receptor retinoic acid receptor-related orphan receptor gamma-t (RORγt) is a transcription factor regulating Th17 cell differentiation and proliferation from naive CD4+ T cells. Since Th17 cells have demonstrated the antitumor efficacy by eliciting remarkable activation of CD8+ T cells, RORγt agonists could be applied as potential small molecule therapeutics for cancer immunotherapy. Based on the previously reported RORγt agonist 1 and its resolved co-crystal structure, a series of new tertiary amines were designed, synthesized and biologically evaluated, yielding optimal moieties with improved chemical properties and biological responses. The combination of these optimal moieties resulted in identification of novel RORγt agonists such as 8b with further elevated RORγt agonism responses at a target-based level as well as in cell-based assays, which provided some structural knowledge for further optimization of RORγt agonists as small molecule therapeutics for cancer immunotherapy.
Highly economical and direct amination of sp3carbon using low-cost nickel pincer catalyst
Brandt, Andrew,Rangumagar, Ambar B.,Szwedo, Peter,Wayland, Hunter A.,Parnell, Charlette M.,Munshi, Pradip,Ghosh, Anindya
, p. 1862 - 1874 (2021/01/20)
Developing more efficient routes to achieve C-N bond coupling is of great importance to industries ranging from products in pharmaceuticals and fertilizers to biomedical technologies and next-generation electroactive materials. Over the past decade, improvements in catalyst design have moved synthesis away from expensive metals to newer inexpensive C-N cross-coupling approaches via direct amine alkylation. For the first time, we report the use of an amide-based nickel pincer catalyst (1) for direct alkylation of amines via activation of sp3 C-H bonds. The reaction was accomplished using a 0.2 mol% catalyst and no additional activating agents other than the base. Upon optimization, it was determined that the ideal reaction conditions involved solvent dimethyl sulfoxide at 110 °C for 3 h. The catalyst demonstrated excellent reactivity in the formation of various imines, intramolecularly cyclized amines, and substituted amines with a turnover number (TON) as high as 183. Depending on the base used for the reaction and the starting amines, the catalyst demonstrated high selectivity towards the product formation. The exploration into the mechanism and kinetics of the reaction pathway suggested the C-H activation as the rate-limiting step, with the reaction second-order overall, holding first-order behavior towards the catalyst and toluene substrate.
Cobalt encapsulated in N?doped graphene sheet for one-pot reductive amination to synthesize secondary amines
Liu, Lin,Li, Wenxiu,Qi, Ran,Zhu, Qingqing,Li, Jing,Fang, Yuzhen,Kong, Xiangjin
, (2021/03/14)
To develop an efficient base-metal reductive amination catalyst for synthesis of secondary amines is still a major challenge. In this study, an efficient N-doped graphene sheet-coated cobalt catalyst (Co@CN-800) was developed through a simple pyrolysis process, which could gave 99.5 % yield of N-benzylaniline by one-pot reductive amination of nitrobenzene with benzaldehyde during at least 5 cycles. Catalyst characterization and control experiments confirmed that the robust catalytic performance of the catalyst is probably due to the synergy effect of in situ generated Co-Nx encapsulated in N?doped graphene layer and appropriate meso-pore structure. Additionally, The substrate adaptability of the catalyst was proved since a variety of corresponding secondary amines were smoothly obtained under relatively mild conditions, which makes the secondary amine synthesis strategy based on Co@CN-800 shows excellent application prospect.
One-pot, chemoselective synthesis of secondary amines from aryl nitriles using a PdPt-Fe3O4nanoparticle catalyst
Byun, Sangmoon,Cho, Ahra,Cho, Jin Hee,Kim, B. Moon
, p. 4201 - 4209 (2020/09/23)
We have developed a new catalytic method for the one-pot, cascade synthesis of unsymmetrical secondary amines via the reductive amination of aryl nitriles with nitroalkanes using a PdPt-Fe3O4 nanoparticle (NP) catalyst. The use of a bimetallic catalyst resulted in enhanced reactivity and selectivity compared to that of either monometallic Pd-Fe3O4 or the Pt-Fe3O4 NP catalyst. Using this bimetallic catalytic system, we were successful in the synthesis of various unsymmetrical secondary amines under mild conditions. However, aryl nitriles containing an electron-donating substituent were rather resistant to the reductive amination, and when hexafluoroisopropanol (HFIP) was used as a co-solvent, the reaction selectivity and yield for unsymmetrical secondary amines increased dramatically. Using the catalyst system, one-pot, gram-scale synthesis of indole was possible from 2-nitrophenylacetonitrile. Due to the magnetic property of the Fe3O4 support, the bimetallic catalyst could easily be recycled using an external magnet at least four times.
Methyl-triflate-mediated dearylmethylation of: N -(arylmethyl)carboxamides via the retro-Mannich reaction induced by electrophilic dearomatization/rearomatization in an aqueous medium at room temperature
Peng, Hui,Ma, Jinhui,Luo, Wenkun,Zhang, Guangwen,Yin, Biaolin
supporting information, p. 2252 - 2256 (2019/05/17)
We have developed a protocol for the dearylmethylation of N-(arylmethyl)carboxamides under metal-free conditions in an aqueous medium at room temperature. This protocol involves methyl triflate-mediated successive C-C and C-N bond cleavages (retro-Mannich reaction) induced by electrophilic dearomatization/rearomatization. The dearomatization/rearomatization strategy can be expected to inspire the development of novel transformations based on the C-C bond cleavage in an environmentally benign manner.
Tertiary amine derivative or salt thereof, preparation method and application thereof
-
Paragraph 0320; 0323; 324; 0325, (2019/01/24)
Belonging to the technical field of chemical medicine, the invention relates to a tertiary amine RORgamma t regulator, in particular to a new tertiary amine compound or salt thereof with RORgamma t inhibition or agonist activity shown as general formula I, a preparation method and a pharmaceutical composition thereof. The tertiary amine compound or a salt thereof provided by the invention can be used for preparation of drugs treating or preventing RORgamma t receptor related diseases.
Biocatalytic N-Alkylation of Amines Using Either Primary Alcohols or Carboxylic Acids via Reductive Aminase Cascades
Ramsden, Jeremy I.,Heath, Rachel S.,Derrington, Sasha R.,Montgomery, Sarah L.,Mangas-Sanchez, Juan,Mulholland, Keith R.,Turner, Nicholas J.
, p. 1201 - 1206 (2019/01/21)
The alkylation of amines with either alcohols or carboxylic acids represents a mild and safe alternative to the use of genotoxic alkyl halides and sulfonate esters. Here we report two complementary one-pot systems in which the reductive aminase (RedAm) from Aspergillus oryzae is combined with either (i) a 1° alcohol/alcohol oxidase (AO) or (ii) carboxylic acid/carboxylic acid reductase (CAR) to affect N-alkylation reactions. The application of both approaches has been exemplified with respect to substrate scope and also preparative scale synthesis. These new biocatalytic methods address issues facing alternative traditional synthetic protocols such as harsh conditions, overalkylation and complicated workup procedures.
Direct Reductive Amination of Carbonyl Compounds with H2 Using Heterogeneous Catalysts in Continuous Flow as an Alternative to N-Alkylation with Alkyl Halides
Laroche, Benjamin,Ishitani, Haruro,Kobayashi, Shū
supporting information, p. 4699 - 4704 (2018/12/04)
A general continuous-flow procedure for direct reductive amination of secondary and primary amines with aromatic and aliphatic aldehydes as well as ketones is reported. The use of hydrogen gas and commercially available Pt/C as a heterogeneous catalyst is a key. In addition to exhibiting an excellent functional group tolerance, this method allows the fast formation of C?N bonds without production of any hazardous chemical waste. Applications to the synthesis of key intermediates toward active pharmaceutical ingredients (Donepezil and Arformoterol/Tamsulosin) are also described. (Figure presented.).
Direct Reductive N-Functionalization of Aliphatic Nitro Compounds
Rauser, Marian,Ascheberg, Christoph,Niggemann, Meike
, p. 3970 - 3974 (2018/02/26)
The first general protocol for the direct reductive N-functionalization of aliphatic nitro compounds is presented. The nitro group is partially reduced to a nitrenoid, with a mild and readily available combination of B2pin2 and zinc organyls. Thereby, the formation of an unstable nitroso intermediate is avoided, which has so far severely limited reductive transformations of aliphatic nitro compounds. The reaction is concluded by an electrophilic amination of zinc organyls.
