37812-47-8Relevant academic research and scientific papers
Electrochemical, Iodine-Mediated α-CH Amination of Ketones by Umpolung of Silyl Enol Ethers
Strehl, Julia,Hilt, Gerhard
supporting information, p. 5968 - 5972 (2020/08/12)
The electrochemical, oxidative Umpolung reaction of silyl enol ethers utilizing simple iodide salts for the synthesis of α-amino ketones is described. The products were isolated in excellent yields of up to 100percent, and various functionalized starting materials were accepted in an undivided electrochemical cell design. Moreover, a sensitivity assessment to ensure an improved reproducibility of the reaction and cyclic voltammetry experiments were performed to postulate a plausible reaction mechanism on their basis.
A proton-responsive annulated mesoionic carbene (MIC) scaffold on IR complex for proton/hydride shuttle: An experimental and computational investigation on reductive amination of aldehyde
Bera, Jitendra K.,Daw, Prosenjit,Din Reshi, Noor U.,Ehmann, Kira R.,H?lscher, Markus,Leitner, Walter,Pandey, Pragati
, p. 3849 - 3863 (2020/11/23)
A Cp*Ir(III) complex (1) bearing a proton-responsive hydroxy unit on an annulated imidazo[1,2-a][1,8]naphthyridine based mesoionic carbene scaffold was synthesized by two different synthetic routes. The molecular structure of 1 revealed an anionic lactam form of the ligand. The acid?base equilibrium between the lactam-lactim tautomers on the ligand scaffold was examined by 1H NMR and UV?vis spectra. The pKa of the appendage ?OH group in the lactim form of 1 was estimated to assess the proton transfer property of the catalyst. The catalytic efficacy of 1 for reductive amination of aldehyde was evaluated by utilizing three different hydrogen sources: molecular H2iPrOH/KOtBu combination, and HCOOH/Et3N (5:2) azeotropic mixture. The HCOOH/Et3N (5:2) azeotropic mixture rotocol was found to be the best amon the three different h dro enation methods. Catalyst 1 hydrogenates imines chemoselectively over carbonyls under the reaction conditions. A range of aldehydes was reductively aminated to the corresponding secondary amines using the HCOOH/Et3N (5:2) azeotropic mixture. Further, catalyst 1 showed high efficiency for the reduction of a wide variety of N-heterocyclic imine derivatives. The lactam-lactim tautomerization of the ligand system is proposed for direct hydrogenation, whereas only the lactam form operates in the strongly basic medium (iPrOH/KOtBu). Under HCOOH/Et3N (5:2) conditions, the lactam scaffold is not protonated; rather, an outer-sphere hydride transfer from formate to the Ir is proposed, which is supported by 1H NMR and DFT calculations. Finally, ligand-promoted hydride transfer from metal-hydride to the protonated imine affords the corresponding amine. A close agreement between the experimentally estimated and computed thermodynamic/kinetic parameters gives credence to the metal-ligand cooperative mechanism for the imine hydrogenation reaction using the HCOOH/Et3N (5:2) azeotropic mixture.
Expanding Water/Base Tolerant Frustrated Lewis Pair Chemistry to Alkylamines Enables Broad Scope Reductive Aminations
Fasano, Valerio,Ingleson, Michael J.
supporting information, p. 2217 - 2224 (2017/02/18)
Lower Lewis acidity boranes demonstrate greater tolerance to combinations of water/strong Br?nsted bases than B(C6F5)3, this enables Si?H bond activation by a frustrated Lewis pair (FLP) mechanism to proceed in the presence of H2O/alkylamines. Specifically, BPh3has improved water tolerance in the presence of alkylamines as the Br?nsted acidic adduct H2O–BPh3does not undergo irreversible deprotonation with aliphatic amines in contrast to H2O–B(C6F5)3. Therefore BPh3is a catalyst for the reductive amination of aldehydes and ketones with alkylamines using silanes as reductants. A range of amines inaccessible using B(C6F5)3as catalyst, were accessible by reductive amination catalysed by BPh3via an operationally simple methodology requiring no purification of BPh3or reagents/solvent. BPh3has a complementary reductive amination scope to B(C6F5)3with the former not an effective catalyst for the reductive amination of arylamines, while the latter is not an effective catalyst for the reductive amination of alkylamines. This disparity is due to the different pKavalues of the water–borane adducts and the greater susceptibility of BPh3species towards protodeboronation. An understanding of the deactivation processes occurring using B(C6F5)3and BPh3as reductive amination catalysts led to the identification of a third triarylborane, B(3,5-Cl2C6H3)3, that has a broader substrate scope being able to catalyse the reductive amination of both aryl and alkyl amines with carbonyls.
A General and Selective Rhodium-Catalyzed Reduction of Amides, N-Acyl Amino Esters, and Dipeptides Using Phenylsilane
Das, Shoubhik,Li, Yuehui,Lu, Liang-Qiu,Junge, Kathrin,Beller, Matthias
supporting information, p. 7050 - 7053 (2016/05/19)
This article describes a selective reduction of functionalized amides, including N-acyl amino esters and dipeptides, to the corresponding amines using simple [Rh(acac)(cod)]. The catalyst shows excellent chemoselectivity in the presence of different sensitive functional moieties. A selective reduction of functionalized amides, including N-acyl amino esters and dipeptides, to the corresponding amines using simple [Rh(acac)(cod)] is described (see scheme). The catalyst shows excellent chemoselectivity in the presence of different sensitive functional moieties. Even the selective reduction of a secondary amide bond in the presence of a ketone is possible.
Pseudorotaxane orientational stereoisomerism driven by π-electron density
Gaeta, Carmine,Talotta, Carmen,Neri, Placido
supporting information, p. 9917 - 9920 (2014/08/18)
Pseudo[2]rotaxane orientational isomers were formed in a stereocontrolled way by exploiting the electron-withdrawing (EW) or electron-donating (ED) effects of para-substituted dibenzylammonium axles threaded through the π-electron rich calixarene cavity, which allow the fine tuning of the weak π-π interactions.
Iridium-catalyzed reduction of secondary amides to secondary amines and imines by diethylsilane
Cheng, Chen,Brookhart, Maurice
, p. 11304 - 11307 (2012/09/05)
Catalytic reduction of secondary amides to imines and secondary amines has been achieved using readily available iridium catalysts such as [Ir(COE) 2Cl]2 with diethylsilane as reductant. The stepwise reduction to secondary amine proceeds through an imine intermediate that can be isolated when only 2 equiv of silane is used. This system requires low catalyst loading and shows high efficiency (up to 1000 turnovers at room temperature with 99% conversion have been attained) and an appreciable level of functional group tolerance.
Zinc-catalyzed chemoselective reduction of tertiary and secondary amides to amines
Das, Shoubhik,Addis, Daniele,Junge, Kathrin,Beller, Matthias
experimental part, p. 12186 - 12192 (2011/11/07)
General and convenient procedures for the catalytic hydrosilylation of secondary and tertiary amides under mild conditions have been developed. In the presence of inexpensive zinc catalysts, tertiary amides are easily reduced by applying monosilanes. Key to success for the reduction of the secondary amides is the use of zinc triflate and disilanes with dual Si-H moieties. The presented hydrosilylations proceed with excellent chemoselectivity in the presence of sensitive ester, nitro, azo, nitrile, olefins, and other functional groups, thus making the method attractive for organic synthesis.
Reductive amination using ammonia borane
Veeraraghavan Ramachandran,Gagare, Pravin D.,Sakavuyi, Kaumba,Clark, Paul
experimental part, p. 3167 - 3169 (2010/08/05)
A variety of primary, secondary, and tertiary amines were prepared in 84-95% yields using ammonia borane for the reductive amination of aldehydes and ketones in the presence of titanium isopropoxide.
A one-pot, solid-phase synthesis of secondary amines from reactive alkyl halides and an alkyl azide
Ayesa, Susana,Samuelsson, Bertil,Classon, Bj?rn
, p. 97 - 99 (2008/09/21)
A one-pot, two-step, polymer-bound, triphenylphosphine-supported synthesis of secondary amines from the corresponding azide and a reactive alkyl halide is described. Georg Thieme Verlag Stuttgart.
Oxidative N-debenzylation of N-benzyl-N-substituted benzylamines catalyzed by horseradish peroxidase
Kim, Sung Soo,Jung, Hwan
, p. 555 - 558 (2007/10/03)
A report on the oxidative N-debenzylation of N-benyl-N-substituted benzylamines catalyzed by horseradish peroxidase was presented. A solution of benzylamine in benzene was added to a benzene solution of p-anisaldehyde in 100 ml flask over 10 minutes. Expulsion of proton and hydroxylation yielding α-hydroxylamines were followed by the formation of benzaldehydes and benzylamines.
