20455-68-9Relevant academic research and scientific papers
A General, Selective, High-Yield N-Demethylation Procedure for Tertiary Amines by Solid Reagents in a Convenient Column Chromatography-like Setup
Rosenau, Thomas,Hofinger, Andreas,Potthast, Antje,Kosma, Paul
, p. 541 - 544 (2004)
(Equation presented) A traditional preparative chromatographic column can be used to achieve quantitative N-demethylation of tertiary N-methylamines and alkaloids. The filling is the crucial part and is loaded with different solid reagents in three reaction zones. The parent compound is charged on the column, and the neat N-demethylated secondary amine leaves the column some minutes later.
Novel Family of (1-aminoalkyl)(trifluoromethyl)- and -(difluoromethyl) phosphinic Acids - Analogues of α-Amino Acids
Pavlenko, Natalia V.,Oos, Tatiana I.,Yagupolskii, Yurii L.,Gerus, Igor I.,Doeller, Uwe,Willms, Lothar
, p. 722 - 731 (2014)
A series of novel (1-aminoalkyl)(trifluoromethyl)- and -(difluoromethyl) phosphinic acids - analogues of proteinogenic and nonproteinogenic α-amino acids were prepared. The synthetic methodology was based on nucleophilic addition of (trifluoromethyl)phosphinic acid or (difluoromethyl)phosphinic acid or its ethyl ester to substrates with C=N or activated C=C double bonds. Analogues of glycine, phenylglycine, alanine, valine, proline, aminomalonic and aspartic acids were thus prepared. Three-component one-pot reactions of (trifluoromethyl)phosphinic acid and dibenzylamine with aldehydes were also tested to prepare the title compounds.
Selenoxide elimination triggers enamine hydrolysis to primary and secondary amines: A combined experimental and theoretical investigation
Bortoli, Marco,Gianoncelli, Alessandra,Ongaro, Alberto,Orian, Laura,Oselladore, Erika,Ribaudo, Giovanni,Zagotto, Giuseppe
, (2021/05/26)
We discuss a novel selenium-based reaction mechanism consisting in a selenoxide elimination-triggered enamine hydrolysis. This one-pot model reaction was studied for a set of substrates. Under oxidative conditions, we observed and characterized the formation of primary and secondary amines as elimination products of such compounds, paving the way for a novel strategy to selectively release bioactive molecules. The underlying mechanism was investigated using NMR, mass spectrometry and density functional theory (DFT).
Lithium compound catalyzed deoxygenative hydroboration of primary, secondary and tertiary amides
Bisai, Milan Kumar,Gour, Kritika,Das, Tamal,Vanka, Kumar,Sen, Sakya S.
supporting information, p. 2354 - 2358 (2021/03/03)
A selective and efficient route for the deoxygenative reduction of primary to tertiary amides to corresponding amines has been achieved with pinacolborane (HBpin) using simple and readily accessible 2,6-di-tert-butyl phenolate lithium·THF (1a) as a catalyst. Both experimental and DFT studies provide mechanistic insight. This journal is
A practical catalytic reductive amination of carboxylic acids
Andrews, Keith G.,Denton, Ross M.,Hirst, David J.,Stoll, Emma L.,Tongue, Thomas,Valette, Damien
, p. 9494 - 9500 (2020/10/02)
We report reductive alkylation reactions of amines using carboxylic acids as nominal electrophiles. The two-step reaction exploits the dual reactivity of phenylsilane and involves a silane-mediated amidation followed by a Zn(OAc)2-catalyzed amide reduction. The reaction is applicable to a wide range of amines and carboxylic acids and has been demonstrated on a large scale (305 mmol of amine). The rate differential between the reduction of tertiary and secondary amide intermediates is exemplified in a convergent synthesis of the antiretroviral medicine maraviroc. Mechanistic studies demonstrate that a residual 0.5 equivalents of carboxylic acid from the amidation step is responsible for the generation of silane reductants with augmented reactivity, which allow secondary amides, previously unreactive in zinc/phenylsilane systems, to be reduced.
Computationally forecasting the effect of dibenzylammonium substituents on pseudorotaxane formation with dibenzo[24]crown-8
Payne, Nicholas A.,Delmas, Luke C.,McDowell, Sean A.C.,Williams, Avril R.
supporting information, p. 5175 - 5179 (2015/08/18)
The ability to predict the relative stabilities of analogous pseudorotaxanes is essential for the synthetic chemist yet simplified computational forecasting approaches remain scarce. Consequently, ten [2]pseudorotaxanes have been assembled (from a series of para-substituted dibenzylammonium ions and dibenzo[24]crown-8) and their experimentally-determined stabilities correlated with two computational parameters closely related to complexation energy. The strongest relationship was obtained from density functional theory calculation of binding energy (R2 = 0.92) while determination of the maximum surface electrostatic potential on the dibenzylammonium ions (a proxy indicator of complex stability) afforded comparable results (R2 = 0.88) with great reduction in computational expense.
Magnesium-catalyzed mild reduction of tertiary and secondary amides to amines
Lampland, Nicole L.,Hovey, Megan,Mukherjee, Debabrata,Sadow, Aaron D.
, p. 4219 - 4226 (2015/11/11)
The first example of a catalytic hydroboration of amides for their deoxygenation to amines is reported. This transformation employs an earth-abundant magnesium-based catalyst. Tertiary and secondary amides are reduced to amines at room temperature in the presence of pinacolborane (HBpin) and catalytic amounts of ToMMgMe (ToM = tris(4,4-dimethyl-2-oxazolinyl)phenylborate). Catalyst initiation and speciation is complex in this system, as revealed by the effects of concentration and order of addition of the substrate and HBpin in the catalytic experiments. ToMMgH2Bpin, formed from ToMMgMe and HBpin, is ruled out as a possible catalytically relevant species by its reaction with N,N-dimethylbenzamide, which gives Me2NBpin and PhBpin through C-N and C-C bond cleavage pathways, respectively. In that reaction, the catalytic product benzyldimethylamine is formed in only low yield. Alternatively, the reaction of ToMMgMe and N,N-dimethylbenzamide slowly gives decomposition of ToMMgMe over 24 h, and this interaction is also ruled out as a catalytically relevant step. Together, these data suggest that catalytic activation of ToMMgMe requires both HBpin and amide, and ToMMgH2Bpin is not a catalytic intermediate. With information on catalyst activation in hand, tertiary amides are selectively reduced to amines in good yield when catalytic amounts of ToMMgMe are added to a mixture of amide and excess HBpin. In addition, secondary amides are reduced in the presence of 10 mol % ToMMgMe and 4 equiv of HBpin. Functional groups such as cyano, nitro, and azo remain intact under the mild reaction conditions. In addition, kinetic experiments and competition experiments indicate that B-H addition to amide C-O is fast, even faster than addition to ester C=O, and requires participation of the catalyst, whereas the turnover-limiting step of the catalyst is deoxygenation.
Copper-catalysed reductive amination of nitriles and organic-group reductions using dimethylamine borane
Van Der Waals, Dominic,Pettman, Alan,Williams, Jonathan M. J.
, p. 51845 - 51849 (2014/12/10)
A heterogeneous copper catalyst, formed in situ, has been shown to dehydrocouple commercially available amine boranes whilst transferring hydrogen for the reduction of selected organic functional groups in an aqueous medium. The catalytic system has also been shown to promote the reductive amination of aryl nitriles. This journal is
A practical procedure for reduction of primary, secondary and tertiary amides to amines
Reeves, Jonathan T.,Tan, Zhulin,Marsini, Maurice A.,Han, Zhengxu S.,Xu, Yibo,Reeves, Diana C.,Lee, Heewon,Lu, Bruce Z.,Senanayake, Chris H.
supporting information, p. 47 - 52 (2013/03/13)
A mild and general procedure for reduction of primary, secondary, and tertiary amides using catalytic triruthenium dodecacarbonyl and 1,1,3,3-tetramethyldisiloxane as reductant is described. The reaction is tolerant of numerous functional groups, and the amine products can often be isolated by direct crystallization as hydrochloride salts. The catalyst and silane are commercially available, air stable, and inexpensive, making the procedure accessible for both laboratory and large-scale applications. Copyright
Cobalt carbonyl-based catalyst for hydrosilylation of carboxamides
Dombray, Thomas,Helleu, Camille,Darcel, Christophe,Sortais, Jean-Baptiste
supporting information, p. 3358 - 3362 (2013/12/04)
The cobalt carbonyl [Co2(CO)8] complex is employed as a useful catalyst for the reduction of tertiary amides to the corresponding tertiary amines using 1,1,3,3-tetramethyldisiloxane (TMDS) and poly(methylhydrosiloxane) (PMHS) as silane reagents under thermal (100 °C) or photo-assisted conditions (UV, 350 nm at room temperature). Of particular interest, a low catalytic amount (0.5 mol%) of [Co2(CO)8] is used to perform the reaction with 2.2 equiv. of PMHS at 100 °C for 3 h. This reaction is the first example of a cobalt-catalyzed hydrosilylation of amides. Copyright
