123330-52-9Relevant academic research and scientific papers
Model compounds study on the network structure of polybenzoxazines
Kim, Ho-Dong,Ishida, Hatsuo
, p. 8320 - 8329 (2003)
The FT-IR and 1H NMR spectra of model dimers, having different molecular sizes and pKa, are investigated in order to understand the differences in the hydrogen-bonded network structures of polybenzoxazines. The correlation between the -OH...N intramolecular hydrogen-bonding interaction and benzoxazine functional groups in the asymmetric dimers is investigated by 1H NMR spectra. While the FT-IR spectra of the model dimers indicate that the nature of hydrogen bonding is closely related to the basicity of the amine constituent, the spectra of the corresponding polymers suggest the existence of different hydrogen-bonding interactions. The existence of phenolic linkage formation and the stability of the Mannich base structure during polymerization are investigated by a dimerization reaction. It is demonstrated that benzoxazines based upon extremely bulky amines do not develop desirable properties due to the extensive degradation process.
A Simple Cobalt(II) Chloride Catalyzed N -Alkylation of Amines with Alcohols
Midya, Siba P.,Mondal, Akash,Begum, Ayesha,Balaraman, Ekambaram
, p. 3957 - 3961 (2017)
A facile cobalt-catalyzed N -alkylation of amines with alcohols using inexpensive, commercially available CoCl 2 ·6H 2 O is reported. Employing this readily available cobalt catalyst, a variety of amines with wide functional group tolerance were selectively alkylated under benign conditions.
Biorenewable carbon-supported Ru catalyst for: N -alkylation of amines with alcohols and selective hydrogenation of nitroarenes
Goyal, Vishakha,Narani, Anand,Natte, Kishore,Poddar, Mukesh Kumar,Ray, Anjan,Sarki, Naina,Tripathi, Deependra
, p. 14687 - 14694 (2021/08/23)
Herein, we developed a renewable carbon-supported Ru catalyst (Ru/PNC-700), which was facilely prepared via simple impregnation followed by the pyrolysis process. The prepared Ru/PNC-700 catalyst demonstrated remarkable catalytic activity in terms of conversion and selectivity towards N-alkylation of anilines with benzyl alcohol and chemoselective hydrogenation of aromatic nitro compounds. In addition, local anesthetic pharmaceutical agents (e.g., butamben and benzocaine), including key drug intermediates, were synthesized in excellent yields under mild conditions and in the presence of water as a green solvent. Moreover, the prepared Ru/PNC-700 catalyst could be easily recovered and reused up to five times without any apparent loss in activity and selectivity.
Platinum Assisted Tandem P–C Bond Cleavage and P–N Bond Formation in Amide Functionalized Bisphosphine o-Ph2PC6H4C(O)N(H)C6H4PPh2-o: Synthesis, Mechanistic, and Catalytic Studies
Balakrishna, Maravanji S.,Kunchur, Harish S.
supporting information, (2022/01/19)
The reactions of amide functionalized bisphosphine o-Ph2PC6H4C(O)N(H)C6H4PPh2-o (1) with platinum salts are described. Treatment of 1 with [Pt(COD)Cl2] yielded a chelate complex, [PtCl2{o-Ph2PC6H4C(O)N(H)C6H4PPh2-o}κ2-P,P] (2), which on subsequent treatment with LiHMDS formed a novel 1,2-azaphospholene-phosphine complex [Pt(C6H5)Cl{o-C6H4{C(O)N(o-PPh2(C6H4))P(Ph)}}κ2-P,P] (3) involving a tandem P–C bond cleavage and P–N bond formation. The same complex 3 on passing dry HCl gas afforded the dichloro complex [PtCl2{o-C6H4{C(O)N(o-PPh2(C6H4))P(Ph)}}κ2-P,P] (5). Complex 2 upon refluxing in toluene or treatment of 1 with [Pt(COD)Cl2] in the presence of a base at room temperature resulted in the pincer complex [PtCl{o-Ph2PC6H4C(O)N(C6H4PPh2-o)}κ3-P,N,P] (4). Reaction of 1 with [Pt(COD)ClMe] at room temperature also afforded the pincer complex [PtMe{o-Ph2PC6H4C(O)N(C6H4PPh2-o)}κ3-P,N,P] (6). Mechanistic studies on 1,2-azaphospholene formation showed the reductive elimination of LiCl to form a phosphonium salt that readily adds one of the P–C bonds oxidatively to the in situ generated Pt0 species to form a chelate complex 3. The analogous palladium complex [PdCl2{o-C6H4{C(O)N(o-PPh2(C6H4))P(Ph)}}κ2-P,P] (7) showed excellent catalytic activity toward N-alkylation of amines with alcohols with a very low catalyst loading (0.05 mol %), and the methodology is very efficient toward the gram-scale synthesis of many N-alkylated amines.
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.
Cross dehydrogenative coupling strategy for allylation of benzylanilines promoted by DDQ
Xiong, Ruimei,Hussain, Muhammad Ijaz,Liu, Qing,Xia, Wen,Xiong, Yan
, (2019/12/11)
A cross dehydrogenative coupling strategy for allylation of benzylanilines promoted by DDQ is reported, which uses nonmetallic quinone DDQ as an oxidant in the allylation of N-benzylanilines under mild conditions. C–C bond with high selectivity and activity was constructed in this reaction and homoallylic amines were obtained with yields of up to 99%.
Alkali Metal–Promoted Facile Synthesis of Secondary Amines from Imines and Carbodiimides
Panda, Tarun K.,Banerjee, Indrani,Sagar, Shweta
, (2020/05/25)
We present here an efficient method for the hydroboration of aldimines (-C=N-) with pinacolborane (HBpin) using an alkali metal catalyst, potassium benzyl. The reaction was accomplished with unprecedented catalytic efficiency under mild and solvent-free conditions to afford the high yield of the corresponding N-boryl amines up to 97percent. Various functionalities on aldimines were incorporated for hydroboration. The corresponding boryl amines were subjected to further hydrolysis to yield the corresponding secondary amines with good yields up to 89percent. This protocol for the reaction demonstrates an atom-economic and green method with diverse imines that bears excellent functional group tolerance. Chemoselective reduction of imines was also attained, with good yields of 74–89percent. We also propose the most plausible mechanism involving the formation of metal hydride as the active pre-catalyst.
Simple reversible fixation of a magnetic catalyst in a continuous flow system: Ultrafast reduction of nitroarenes and subsequent reductive amination using ammonia borane
Byun, Sangmoon,Cho, Ahra,Kang, Dong Yun,Kim, B. Moon,Kim, Ha Joon,Kim, Hong Won,Kim, Seong Min,Lei, Cao,Park, Jin Kyoon
, p. 944 - 949 (2020/03/11)
Continuous reductive amination of aldehydes with nitroarenes over a Pd-Pt-Fe3O4 catalyst was performed. We used NH3BH3 as not only a hydrogen source for nitro reduction, but also a reductant for imine reduction. Secondary aromatic amines were obtained in the continuous flow reaction in good to excellent yields.
Switching the N-Alkylation of Arylamines with Benzyl Alcohols to Imine Formation Enables the One-Pot Synthesis of Enantioenriched α-N-Alkylaminophosphonates
Hofmann, Natalie,Hultzsch, Kai C.
supporting information, p. 3105 - 3111 (2019/06/08)
The selective N-alkylation of anilines with benzylic alcohols can be switched in favor of the dehydrogenative condensation process using the nitrile-ligated Kn?lker's complex by conducting the reaction either in a closed system under inert conditions, or in an open system in air. The selective formation of imines, containing reactive C=N bonds, provides an opportunity towards further functionalization. Indeed, a one-pot three-component condensation of alcohols, amines and phosphites, promoted by an iron-based Kn?lker-type complex in combination with a chiral BINOL-based phosphoric acid, provides access to enantioenriched α-N-alkylaminophosphonates.
A Highly Active PN3 Manganese Pincer Complex Performing N-Alkylation of Amines under Mild Conditions
Homberg, Leonard,Roller, Alexander,Hultzsch, Kai C.
supporting information, (2019/05/07)
A highly active Mn(I) catalyst based on a nonsymmetric PN3-ligand scaffold for the N-alkylation of amines with alcohols utilizing the borrowing hydrogen methodology is reported. A broad range of anilines and the more challenging aliphatic amines were alkylated with primary and secondary alcohols. Moreover, the combination of low catalyst loadings and mild reaction conditions provides high efficiency for this atom-economic transformation.
