72641-00-0Relevant academic research and scientific papers
Two-Step Protocol for Iodotrimethylsilane-Mediated Deoxy-Functionalization of Alcohols
Chen, Yuming,He, Ru,Song, Hongjian,Yu, Guoqing,Li, Chenglin,Liu, Yuxiu,Wang, Qingmin
, p. 1179 - 1183 (2021/02/01)
We have developed a two-step protocol for iodotrimethylsilane-mediated deoxy-functionalization of primary and secondary alcohols to afford products containing a C?N, C?S, or C?O bond. In the first step the alcohol undergoes iodination with iodotrimethylsilane, and in the second, the iodine atom is replaced by a N, S, or O nucleophile. Compared with traditional Mitsunobu reaction, non-acidic pre-nucleophiles can be used, and the reaction proceeds with retention of configuration. This operationally simple, highly efficient protocol can be used for some natural products and small-molecule drugs containing hydroxy-group.
Construction of α-Alkylated Amines by Iridium Complex-Catalyzed One-Step Transfer Hydrogenation of C=C and C=N Bonds
Xia, Yanping,Ouyang, Lu,Liao, Jianhua,Yang, Xiao,Luo, Renshi
supporting information, p. 1821 - 1827 (2021/02/22)
Hydrogenation of C=C bond and reductive amination are important transformations utilized in chemistry. An environmentally friendly, efficient, and facile one-pot transfer hydrogenation of C=C bond of enones and reductive amination of C=N bond of imines are reported using iridium complex as catalysts and formic acid as hydrogen source in aqueous medium. In this catalytic system, a wide range of α-alkylated amines were obtained in excellent yields by one-pot transfer hydrogenation of C=C bond and reductive amination. The practical application of this protocol is characterized by gram-scale transformation.
One-Pot Synthesis of Chiral N-Arylamines by Combining Biocatalytic Aminations with Buchwald–Hartwig N-Arylation
Ahmed, Syed T.,Cosgrove, Sebastian C.,Parmeggiani, Fabio,Thompson, Matthew P.,Turner, Nicholas J.
supporting information, p. 18156 - 18160 (2020/08/13)
The combination of biocatalysis and chemo-catalysis increasingly offers chemists access to more diverse chemical architectures. Here, we describe the combination of a toolbox of chiral-amine-producing biocatalysts with a Buchwald–Hartwig cross-coupling reaction, affording a variety of α-chiral aniline derivatives. The use of a surfactant allowed reactions to be performed sequentially in the same flask, preventing the palladium catalyst from being inhibited by the high concentrations of ammonia, salts, or buffers present in the aqueous media in most cases. The methodology was further extended by combining with a dual-enzyme biocatalytic hydrogen-borrowing cascade in one pot to allow for the conversion of a racemic alcohol to a chiral aniline.
One-Pot Transfer Hydrogenation Reductive Amination of Aldehydes and Ketones by Iridium Complexes “on Water”
Ouyang, Lu,Xia, Yanping,Liao, Jianhua,Luo, Renshi
, p. 6387 - 6391 (2020/09/11)
An efficient and practical one-pot transfer hydrogenation reductive amination of aldehydes and ketones with amines has been developed by using iridium complexes as catalysts and formic acid as hydrogen source in aqueous solution, providing an environmentally friendly methodology for the construction of a wide range of functionalized amine compounds in excellent yields (≈ 80 %-95 %). This effective methodology can be scaled up to gram scale with 0.1 mol-% catalyst loading and also be employed in the synthesis of medical substances such as Meclizine.
Reductive Amination by Photoredox Catalysis and Polarity-Matched Hydrogen Atom Transfer
Guo, Xingwei,Wenger, Oliver S.
supporting information, p. 2469 - 2473 (2018/01/27)
The excitation of a RuII photosensitizer in the presence of ascorbic acid leads to the reduction of iminium ions to electron-rich α-aminoalkyl radical intermediates, which are rapidly converted into reductive amination products by thiol-mediated hydrogen atom transfer (HAT). As a result, the reductive amination of carbonyl compounds with amines by photoredox catalysis proceeds in good to excellent yields and with broad substrate scope and good functional group tolerance. The three key features of this work are 1) the rapid interception of electron-rich α-aminoalkyl radical intermediates by polarity-matched HAT in a photoredox reaction, 2) the method of reductive amination by photoredox catalysis itself, and 3) the application of this new method for temporally and spatially controlled reactions on a solid support, as demonstrated by the attachment of a fluorescent dye on an activated cellulose support by photoredox-catalyzed reductive amination.
First efficient two-step/one-pot zirconium (IV)isopropoxide-mediated reductive amination of carbonyl compounds
Pieri, Cyril,Brunel, Jean Michel
, p. 448 - 456 (2015/06/22)
An efficient method for the synthesis of various primary and secondary amines through a zirconium(IV) isopropoxide-mediated reductive amination reaction of aldehydes and ketones is reported. A series of different aldehydes, ketones and amines were used leading to the expected amino products in moderate to excellent yields. The mechanistic rationale of this reaction has been postulated through the formation of a transient imine species and a diastereoselective version using (R)-phenylethylamine as chiral inducer led to the expected products in moderate to excellent yields and with diastereoselectivities up to 100%.
CATALYST COMPOUNDS
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Paragraph 0314; 0326, (2015/03/28)
The present invention relates to an iridium-based catalyst compound for hydrogenating reducible moieties, especially imines and iminiums, the catalyst compounds being defined by the formulas: where ring B is either itself polycyclic, or ring B together with R is polycyclic. The catalysts of the invention are particularly effective in reductive amination procedures 10 which involve the in situ generation of the imine or iminium under reductive hydrogenative conditions.
A 2,6-bis(phenylamino)pyridinato titanium catalyst for the highly regioselective hydroaminoalkylation of styrenes and 1,3-butadienes
Doerfler, Jaika,Preuss, Till,Schischko, Alexandra,Schmidtmann, Marc,Doye, Sven
supporting information, p. 7918 - 7922 (2014/08/05)
The C-C bond forming catalytic hydroaminoalkylation of terminal alkenes, 1,3-dienes, or styrenes allows a direct and highly atom efficient (100 %) synthesis of amines which can result in the formation of two regioisomers, the linear and the branched product. We present a new titanium catalyst with 2,6-bis(phenylamino)pyridinato ligands for intermolecular hydroaminoalkylation reactions of styrenes and 1-phenyl-1,3-butadienes that delivers the corresponding linear hydroaminoalkylation products with excellent regioselectivities. Linear progress: A new Ti complex with 2,6-bis(phenylamino) pyridinato ligands catalyzes highly regioselective hydroaminoalkylation reactions of styrenes. The process that directly gives access to the corresponding linear hydroaminoalkylation products offers a new and flexible synthetic approach towards pharmaceutically important 3-arylpropylamines. It is also possible to convert (E)-1-phenyl-1,3-butadienes into the corresponding linear products.
Fast reductive amination by transfer hydrogenation "on water"
Lei, Qian,Wei, Yawen,Talwar, Dinesh,Wang, Chao,Xue, Dong,Xiao, Jianliang
supporting information, p. 4021 - 4029 (2013/04/10)
Reductive amination of various ketones and aldehydes by transfer hydrogenation under aqueous conditions has been developed, by using cyclometallated iridium complexes as catalysts and formate as hydrogen source. The pH value of the solution is shown to be critical for a high catalytic chemoselectivity and activity, with the best pH value being 4.8. In comparison with that in organic solvents, the reductive amination in an aqueous phase is faster, and the molar ratio of the substrate to the catalyst (S/C) can be set as high as 1×105, the highest S/C value ever reported in reductive amination reactions. The catalyst is easy to access and the reaction is operationally simple, allowing a wide range of ketones and aldehydes to react with various amines in high yields. The protocol provides a practical and environmental friendly new method for the synthesis of amine compounds. Greener amine synthesis: A versatile reductive amination protocol has been developed. By using an iridium catalyst in water, a broad range of ketones and aldehydes react with amines to afford various new amines in good yields (see scheme), with molar ratios of the substrate to the catalyst (S/C) as high as 1×10 5. The pH of the reaction solution plays a key role, regulating both the catalytic activity and the selectivity. Copyright
CATALYST COMPOUNDS
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Paragraph 00163; 00175, (2013/11/05)
The present invention relates to an iridium-based catalyst compound for hydrogenating reducible moieties, especially imines and iminiums, the catalyst compounds being defined by the formulas: where ring B is either itself polycyclic, or ring B together with R is polycyclic. The catalysts of the invention are particularly effective in reductive amination procedures 10 which involve the in situ generation of the imine or iminium under reductive hydrogenative conditions.
