7375-45-3Relevant academic research and scientific papers
Mimicking transition metals in borrowing hydrogen from alcohols
Banik, Ananya,Ahmed, Jasimuddin,Sil, Swagata,Mandal, Swadhin K.
, p. 8353 - 8361 (2021/07/02)
Borrowing hydrogen from alcohols, storing it on a catalyst and subsequent transfer of the hydrogen from the catalyst to anin situgenerated imine is the hallmark of a transition metal mediated catalyticN-alkylation of amines. However, such a borrowing hydrogen mechanism with a transition metal free catalytic system which stores hydrogen molecules in the catalyst backbone is yet to be established. Herein, we demonstrate that a phenalenyl ligand can imitate the role of transition metals in storing and transferring hydrogen molecules leading to borrowing hydrogen mediated alkylation of anilines by alcohols including a wide range of substrate scope. A close inspection of the mechanistic pathway by characterizing several intermediates through various spectroscopic techniques, deuterium labelling experiments, and DFT study concluded that the phenalenyl radical based backbone sequentially adds H+, H˙ and an electron through a dearomatization process which are subsequently used as reducing equivalents to the C-N double bond in a catalytic fashion.
Pyridine mediated transition-metal-free direct alkylation of anilines using alcohols: via borrowing hydrogen conditions
Pothikumar, Rajagopal,Bhat, Venugopal T,Namitharan, Kayambu
supporting information, p. 13607 - 13610 (2020/11/17)
Herein, we report pyridine and other similar azaaromatics as efficient biomimetic hydrogen shuttles for a transition-metal-free direct N-alkylation of aryl and heteroaryl amines using a variety of benzylic and straight chain alcohols. Mechanistic studies including deuterium labeling and the isolation of dihydro-intermediates of the benzannulated pyridine confirmed the role of pyridine and a borrowing hydrogen process operating in these reactions. In addition, we have extended this methodology for the development of dehydrogenative synthesis of quinolines and indoles, as well as the transfer hydrogenation of ketones. This journal is
Zinc-Catalyzed N-Alkylation of Aromatic Amines with Alcohols: A Ligand-Free Approach
Sankar, Velayudham,Kathiresan, Murugavel,Sivakumar, Bitragunta,Mannathan, Subramaniyan
supporting information, p. 4409 - 4414 (2020/09/01)
An efficient zinc-catalyzed N-alkylation reaction of aromatic amines was achieved using aliphatic, aromatic, and heteroaromatic alcohols as the alkylating reagent. A variety of aniline derivatives, including heteroaromatic amines, underwent the N-alkylation reaction and furnished the corresponding monoalkylated products in good to excellent yields. The application of the reaction is also further demonstrated by the synthesis of a 2-phenylquinoline derivative from acetophenone and 2-aminobenzyl alcohol. Deuterium labeling experiments show that the reaction proceeds via a borrowing hydrogen process. (Figure presented.).
A nanoscale iron catalyst for heterogeneous direct: N - And C -alkylations of anilines and ketones using alcohols under hydrogen autotransfer conditions
Nallagangula, Madhu,Sujatha, Chandragiri,Bhat, Venugopal T.,Namitharan, Kayambu
supporting information, p. 8490 - 8493 (2019/07/22)
Here, we report a commercially available nanoscale Fe catalyst for heterogeneous direct N- and C-alkylation reactions of anilines and methyl ketones with alcohols. A hydrogen autotransfer mechanism has been found to operate in these reactions by deuterium labelling studies. In addition, dehydrogenative quinoline synthesis has been demonstrated from amino benzyl alcohols and acetophenones.
Insight into O2-promoted base-catalyzed N-alkylation of amines with alcohols
Wang, Chao,Chen, Changpeng,Han, Jian,Zhang, Jingyu,Yao, Yingming,Zhao, Yingsheng
supporting information, p. 2972 - 2977 (2015/04/27)
A highly efficient and practical transition-metal-free CsOH/O2 catalyst system was developed for the N-alkylation of amines with alcohols under argon. This strategy was compatible with many alcohols and exhibits excellent functional group tolerance. More significantly, the selective formation of secondary amines was achieved in excellent yields. The detailed mechanistic study gave a clear understanding of the role of base and oxygen in the catalytic cycle.
Structure-dependent tautomerization induced catalyst-free autocatalyzed N-alkylation of heteroaryl amines with alcohols
Li, Shuangyan,Li, Xiaohui,Li, Qiang,Yuan, Qiaochao,Shi, Xinkang,Xu, Qing
supporting information, p. 3260 - 3265 (2015/06/25)
Catalyst-free autocatalyzed dehydrative N-alkylation reactions of 2-aminobenzothiazoles, 2-aminopyrimidines, and 2-aminopyrazine with primary and secondary alcohols have been achieved for efficient, practical, and green synthesis of the versatile heteroaryl amine derivatives. These reactions were interestingly induced by structure-dependent tautomeric equilibria of the heteroaryl amines via MPV-O transfer hydrogenation of the imino tautomers by alcohols to give aldehydes as the key initiating step.
Selective Monoarylation of Primary Amines Using the Pd-PEPPSI-IPentCl Precatalyst
Sharif, Sepideh,Rucker, Richard P.,Chandrasoma, Nalin,Mitchell, David,Rodriguez, Michael J.,Froese, Robert D. J.,Organ, Michael G.
supporting information, p. 9507 - 9511 (2015/08/11)
A single set of reaction conditions for the palladium-catalyzed amination of a wide variety of (hetero)aryl halides using primary alkyl amines has been developed. By combining the exceptionally high reactivity of the Pd-PEPPSI-IPentCl catalyst (PEPPSI=pyridine enhanced precatalyst preparation, stabilization, and initiation) with the soluble and nonaggressive sodium salt of BHT (BHT=2,6-di-tert-butyl-hydroxytoluene), both six- and five-membered (hetero)aryl halides undergo efficient and selective amination.
Towards aryl C-N bond formation in dynamic thin films
Gandy, Michael N.,Raston, Colin L.,Stubbs, Keith A.
supporting information, p. 4594 - 4597 (2014/06/24)
C-N bond forming reactions are important in organic chemistry. A thin film microfluidic vortex fluidic device (VFD) operating under confined mode affords N-aryl compounds from 2-chloropyrazine and the corresponding amine, without the need for a transition
Sodium hydroxide catalyzed N-alkylation of (hetero) aromatic primary amines and N1,C5-dialkylation of 4-phenyl-2-aminothiazoles with benzyl alcohols
Donthiri, Ramachandra Reddy,Pappula, Venkatanarayana,Chandra Mohan, Darapaneni,Gaywala, Hiren H.,Adimurthy, Subbarayappa
, p. 6775 - 6781 (2013/07/26)
In the presence of a catalytic amount of NaOH, the selective N-alkylation of various heteroaromatic primary amines is reported. With 1 equiv of NaOH, N1,C5-dialkylation of 4-phenyl-2-aminothiazoles has been investigated. Reaction of in situ generated aldehyde with amine yields the N-alkylated and N1,C5-dialkylated products through hydride ion transformation from alcohol.
Buchwald-Hartwig amination of (hetero)aryl chlorides by employing Mor-DalPhos under aqueous and solvent-free conditions
Tardiff, Bennett J.,Stradiotto, Mark
experimental part, p. 3972 - 3977 (2012/08/27)
We report on the application of the [Pd(cinnamyl)Cl]2/Mor- DalPhos catalyst system in the Buchwald-Hartwig amination of (hetero)aryl chlorides with primary or secondary amines conducted either under aqueous conditions without the use of co-solvents and/or surfactants or under solvent-free conditions (52 examples). We have established that reactions of this type can be conducted without the rigorous exclusion of air, and in the case of the solvent-free reactions, we have demonstrated that appropriately selected liquid and solid reagents can be employed successfully.
