- Iron-Catalyzed Reductive Amination of Aldehydes in Isopropyl Alcohol/Water Media as Hydrogen Sources
-
Reductive amination can be carried in i-PrOH/H2O as hydrogen sources using commercially available iron carbonyl complexes. Within an aqueous alkaline environment, a hydridocarboferrate is formed and its reducing potential is exploited for hydrogenation of the imine (or iminium ion) obtained in situ from aldehydes or ketones, and primary or secondary amines in almost equimolar ratio. This completely sustainable and hydrogen-free process proceeds at 100 °C using Fe3(CO)12 as catalyst precursor under convectional heating while Fe2(CO)9 gave better results when the reaction was carried out under MW dielectric heating. Both enolizable and non-enolizable aldehydes may be successfully employed in reactions with aliphatic and aromatic amines. (Figure presented.).
- Petricci, Elena,Santillo, Niccolò,Castagnolo, Daniele,Cini, Elena,Taddei, Maurizio
-
-
Read Online
- Towards the Development of Frustrated Lewis Pair (FLP) Catalyzed Hydrogenations of Tertiary and Secondary Carboxylic Amides
-
The development of the frustrated Lewis pair catalyzed hydrogenation of tertiary and secondary amides is reviewed. Detailed insight into our strategies in order to overcome challenges during the reaction development process is provided. Furthermore, the d
- K?ring, Laura,Paradies, Jan,Sitte, Nikolai A.
-
supporting information
p. 1287 - 1300
(2022/01/20)
-
- Metal-Free Synthesis of Heteroaryl Amines or Their Hydrochlorides via an External-Base-Free and Solvent-Free C-N Coupling Protocol
-
Herein, a metal-free and solvent-free protocol was developed for the C-N coupling of heteroaryl halides and amines, which afforded numerous heteroaryl amines or their hydrochlorides without any external base. Further investigations elucidated that the basicity of amines and specific interactions derived from the X-ray crystallography analysis of 3j′·HCl played pivotal roles in the reactions. Moreover, this protocol was scalable to gram scales and applicable to drug molecules, which demonstrated its practical value for further applications.
- Fan, Guang-Gao,Jiang, Bo-Wen,Sang, Wei,Cheng, Hua,Zhang, Rui,Yu, Bao-Yi,Yuan, Ye,Chen, Cheng,Verpoort, Francis
-
p. 14627 - 14639
(2021/11/01)
-
- Method for preparing amine compound by reducing amide compound
-
The invention relates to a method for preparing an amine compound by reducing an amide compound, which comprises the following steps: in a protective atmosphere, mixing the amide compound or cyclic amide, a zirconium metal catalyst and pinacol borane, carrying out amide reduction reaction at room temperature, and carrying out aftertreatment by using an ether solution of hydrogen chloride after 12-48 hours to obtain an amine hydrochloride compound. The method is simple to operate, low in cost, good in functional group tolerance and wide in substrate range.
- -
-
Paragraph 0202-0204
(2021/02/10)
-
- Photoredox-Catalyzed Addition of Carbamoyl Radicals to Olefins: A 1,4-Dihydropyridine Approach
-
Functionalization with C1-building blocks are key synthetic methods in organic synthesis. The low reactivity of the most abundant C1-molecule, carbon dioxide, makes alternative carboxylation reactions with CO2-surrogates especially important. We report a photoredox-catalyzed protocol for alkene carbamoylations. Readily accessible 4-carboxamido-Hantzsch esters serve as convenient starting materials that generate carbamoyl radicals upon visible light-mediated single-electron transfer. Addition to various alkenes proceeded with high levels of regio- and chemoselectivity.
- Cardinale, Luana,Konev, Mikhail O.,Jacobi von Wangelin, Axel
-
supporting information
p. 8239 - 8243
(2020/06/20)
-
- N-Methylation and Trideuteromethylation of Amines via Magnesium-Catalyzed Reduction of Cyclic and Linear Carbamates
-
A new reduction of carbamates to N-methyl amines is presented. The magnesium-catalyzed reduction reaction allows the conversion of cyclic and linear carbamates, including N-Boc protected amines, into the corresponding N-methyl amines and amino alcohols which are of significant interest due to their presence in many biologically active molecules. Furthermore, the reduction can be extended to the formation of N-trideuteromethyl labeled amines.
- Magre, Marc,Szewczyk, Marcin,Rueping, Magnus
-
supporting information
p. 3209 - 3214
(2020/04/10)
-
- Transition metal-free catalytic reduction of primary amides using an abnormal NHC based potassium complex: Integrating nucleophilicity with Lewis acidic activation
-
An abnormal N-heterocyclic carbene (aNHC) based potassium complex was used as a transition metal-free catalyst for reduction of primary amides to corresponding primary amines under ambient conditions. Only 2 mol% loading of the catalyst exhibits a broad substrate scope including aromatic, aliphatic and heterocyclic primary amides with excellent functional group tolerance. This method was applicable for reduction of chiral amides and utilized for the synthesis of pharmaceutically valuable precursors on a gram scale. During mechanistic investigation, several intermediates were isolated and characterized through spectroscopic techniques and one of the catalytic intermediates was characterized through single-crystal XRD. A well-defined catalyst and isolable intermediate along with several stoichiometric experiments, in situ NMR experiments and the DFT study helped us to sketch the mechanistic pathway for this reduction process unravelling the dual role of the catalyst involving nucleophilic activation by aNHC along with Lewis acidic activation by K ions.
- Bhunia, Mrinal,Sahoo, Sumeet Ranjan,Das, Arpan,Ahmed, Jasimuddin,Sreejyothi,Mandal, Swadhin K.
-
p. 1848 - 1854
(2020/03/03)
-
- Erratum: Redox-Noninnocent Ligand-Supported Vanadium Catalysts for the Chemoselective Reduction of C=X (X = O, N) Functionalities (Journal of the American Chemical Society (2019) 141:38 (15230-15239) DOI: 10.1021/jacs.9b07062)
-
Pages 15232, 15233, and 15236. In the original paper, the doublet wave functions for 21 and 21a/21b were incorrectly (Figure Presented). reported as spin-contaminated in sections 2.3 and 2.8 (Figure 3 and Scheme 9, respectively.) This comes from the incorrectly reported expected eigenvalue of 0.75 for the spin-squared operator ??2? for the antiferromagnetically coupled doublet |↓?L|↑↑?V state (originally given in the Supporting Information). The correct expected eigenvalue for the |↓?L|↑↑?V state should be 1.75. The wave functions for 21 and 21a/21b (eigenvalues 1.79 and 1.77/1.66, respectively) are therefore not spincontaminated. The corrected Figure 3 and Scheme 9 are presented below. A corrected Supporting Information file is also provided. The corrections do not affect any of the conclusions of the Article, but slightly decrease the gap between the quartet and doublet spin surfaces. Scheme 3 has been also corrected to reflect the fact that (CH3)3SiCH2 ? radicals can only react based on spin conservation.
- Zhang, Guoqi,Wu, Jing,Zheng, Shengping,Neary, Michelle C.,Mao, Jincheng,Flores, Marco,Trovitch, Ryan J.,Dub, Pavel A.
-
supporting information
p. 16507 - 16509
(2020/10/14)
-
- Magnesium-catalyzed mild reduction of tertiary and secondary amides to amines
-
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.
- Lampland, Nicole L.,Hovey, Megan,Mukherjee, Debabrata,Sadow, Aaron D.
-
p. 4219 - 4226
(2015/11/11)
-
- Process for the preparation of N-alkyl-N-methyl-3-hydroxy-3-(2-thienyl)-propylamines
-
The present invention relates to an improved process for preparing chiral N-substituted N-methyl-3-hydroxy-3-(2-thienyl)-propylamine on an industrial scale using an asymmetric hydrogenation as a key step and optionally a special sequence of subsequent steps, using a catalyst system consisting of rhodium and (2R, 4R)-4-(dicyclohexylphosphino)-2-(diphenyl-phosphino-methyl)-N-methyl-aminocarbonyl-pyrrolidine.
- -
-
Page/Page column 3-4
(2010/02/13)
-
- METHOD OF TREATING DISORDERS OF THE DOPAMINERGIC SYSTEMS USING 2,5-DIAMINOTETRALINES
-
The invention relates to novel 2,5-diaminotetralines of the formula: STR1 wherein R1, R2, R3 and R4 are defined herein, processes for preparing them and their use in pharmaceutical compositions. The novel 2, 5-diaminotetralines are useful in treating diseases caused by disorders of the dopaminergic systems.
- -
-
-