- Reduction of Amides to Amines under Mild Conditions via Catalytic Hydrogenation of Amide Acetals and Imidates
-
A simple and general protocol was developed for selective conversion of amides into amines. Amides were converted into amide acetals and imido esters by O-alkylation and then hydrogenated without isolation into amines under very mild reaction conditions over standard hydrogenation catalysts. Triethyloxonium tertafluoroborate, methyl trifluoromethanesulfonate, dimethyl sulfate and ethyl chloroformate were validated as alkylating agent. The synthetic utility of this approach was demonstrated by the selective carbonyl reduction of peptide groups. Carbonyl reduction of peptide group proceeds chemoselective without racemization of the neighboring chiral center. (Figure presented.).
- Kadyrov, Renat
-
p. 185 - 191
(2018/11/23)
-
- Catalytic Hydrogenation for Producing Amines from Carboxylic Acid Amides, Carboxylic Acid Diamides, Di-, Tri-, or Polypeptides, or Peptide Amides
-
The present invention relates to a process for the preparation of amines, comprising the following steps: a. reaction of a (i) carboxylic acid amide of the general formula (I), or (ii) carboxylic acid diamide of the general formula (II), or (iii) di-, tri- or polypeptide, or (iv) peptide amide with carboxy-terminal amide function with an alkylating agent, b. addition of a hydrogenation catalyst to the reaction mixture in a molar ratio of from 1:10 to 1:100 000, based on carboxylic acid amide, carboxylic acid diamide, di-, tri- or polypeptide or peptide amide, c. reaction of the reaction mixture with hydrogen, where a hydrogen pressure of from 0.1 bar to 200 bar is established and where a temperature in a range of from 0° C. to 250° C. is established.
- -
-
Paragraph 185-186
(2016/10/11)
-
- Aerobic Oxidation of Cyclic Amines to Lactams Catalyzed by Ceria-Supported Nanogold
-
Abstract: The oxidative transformation of cyclic amines to lactams, which are important chemical feedstocks, is efficiently catalyzed by CeO2-supported gold nanoparticles (Au/CeO2) and Aerosil 200 in the presence of an atmosphere of O2. The complete conversion of pyrrolidine was achieved in 6.5?h at 160 °C, affording a 97 % yield of the lactam product 2-pyrrolidone (γ-butyrolactam), while 2-piperidone (δ-valerolactam) was synthesized from piperidine (83 % yield) in 2.5?h. Caprolactam, the precursor to the commercially important nylon-6, was obtained from hexamethyleneimine in 37 % yield in 3?h. During the oxidation of pyrrolidine, two transient species, 5-(pyrrolidin-1-yl)-3,4-dihydro-2H-pyrrole (amidine-5) and 4-amino-1-(pyrrolidin-1-yl)butan-1-one, were observed. Both of these compounds were oxidized to 2-pyrrolidone under catalytic conditions, indicating their role as intermediates in the reaction pathway. In addition to the reactions of cyclic secondary amines, Au/CeO2 also efficiently catalyzes the oxidation of N-methyl cyclic tertiary amines to the corresponding lactams at 80 and 100 °C. Graphical Abstract: [Figure not available: see fulltext.]
- Dairo, Taiwo O.,Nelson, Nicholas C.,Slowing, Igor I.,Angelici, Robert J.,Woo, L. Keith
-
p. 2278 - 2291
(2016/11/09)
-
- Aerobic lactonization of diols by biomimetic oxidation
-
Coming up for air: Highly efficient aerobic lactonization can be carried out by a biomimetic oxidation system based on coupled redox catalysts (ruthenium catalyst and electron transfer mediators). This system leads to a low-energy electron transfer from diol to molecular oxygen. Various diols were aerobically oxidized to the corresponding five- to nine-membered lactones in good to high yields under mild reaction conditions (see scheme).
- Endo, Yoshinori,Baeckvall, Jan-E.
-
supporting information; experimental part
p. 12596 - 12601
(2011/12/03)
-
- Oxidant-free lactonization of diols using a hydrotalcite-supported copper catalyst
-
We newly synthesized well-crystallized hydrotalcite-supported copper nanoparticles, denoted as Cu/HT(c), which acted as a highly efficient heterogeneous catalyst for oxidant-free lactonization of various diols under liquid-phase conditions. The Cu/HT(c) catalyst could be recovered by simple filtration and reused without the significant loss of its activity and selectivity.
- Mikami, Yusuke,Ebata, Kaori,Mitsudome, Takato,Mizugaki, Tomoo,Jitsukawa, Koichiro,Kaneda, Kiyotomi
-
experimental part
p. 855 - 861
(2010/09/16)
-
- Supported gold nanoparticles as a reusable catalyst for synthesis of lactones from diols using molecular oxygen as an oxidant under mild conditions
-
The oxidative lactonization of various diols using molecular oxygen as a primary oxidant can be efficiently catalyzed by hydrotalcite-supported Au nanoparticles (Au/HT). For instance, lactonization of 1,4-butanediol gave γ-butyrolactone with an excellent turnover number of 1400. After lactonization, the Au/HT can be recovered by simple filtration and reused without any loss of its activity and selectivity.
- Mitsudome, Takato,Noujima, Akifumi,Mizugaki, Tomoo,Jitsukawa, Koichiro,Kaneda, Kiyotomi
-
experimental part
p. 793 - 797
(2010/04/23)
-
- Disproportionation reactions from glyoxal and difunctional basic molecules
-
Glyoxal was reacted with basic difunctional molecules in order to study the disproportionation reaction.Symmetrical and unsymmetrical 1,2-diamines gave rise to piperazinones; their 1,3-diamine analogues yielded hexahydrodiazepinones; and β-aminoalcohols yielded morpholinones and hydroxyamino acids.Aminoamides gave the expected piperazinediones in low yields and no reaction was observed with diamides.The first step of the reaction consists of the formation of dihydroxy compounds, from which the more basic function assists the departure of OH, providing the expected more stable iminium ion.The observed regioselectivity is consistent with the relative basicities of the two functions; a 100percent regioselectivity is observed with aminoalcohols (giving way to morpholinones and not to amides), a good regiposelectivity with most of N-alkyl-N'-aryl-diamines and a rather low one with N-methyl-N'-ethyl- or N-methyl-N'-p-methoxyphenyl-diamines.Geometry factors were related to the better yield obtained with 1,2-diamines compared with 1,3-diamines.The mechanism was investigated.When deutared glyoxal and diamines were reacted in D2O, incorporation of deuterium was observed, in accordance with the formation of an enolate in the course of the oxidoreduction.The low reactivity of aminoamides and the observed regioselectivities could be related to both the weak basicity of the function that is supposed to allow the formation of the iminium ion and the basicity of the other function that accepts a positive charge and which, if too weak, impedes the reaction because of the instability of the intermediate iminium ion. glyoxal / disproportionation rules / basic difunctional molecules
- Chassonnery, Dominique,Chastrette, Francine,Chastrette, Maurice,Blanc, Alain,Mattioda, Georges
-
p. 188 - 199
(2007/10/02)
-
- Preparation of alkyl morpholinones
-
A 4-alkyl-2-morpholinone is prepared by reacting glyoxal with a C1 -C18 N-alkylmonoethanolamine in solution in a solvent that azeotropes with water at a temperature of about -10° to 20° C. for about 1 to 5 hours and by then heating the reaction mixture to a temperature of at least about 110° C. to remove an azeotrope of water and solvent from the mixture to thereby substantially selectively convert the C1 -C18 N-alkylmonoethanolamine to the corresponding 4-alkyl-2-morpholinone.
- -
-
-
- GIF OXIDATION OF SOME ALICYCLIC AMINES
-
The Gif oxidation of seven alicyclic tertiary amines leads essentially to the formation of lactams.The structure of the products present in trace amounts supports the mechanistic hypothesis previously advanced.The structures of the oxidation products were investigated using high performance GC-MS system.
- Boivin, J.,Gaudin, D.,Labrecque, D.,Jankowski, K.
-
p. 2281 - 2282
(2007/10/02)
-
- Nucleophilic Ring-Opening Reactions of Morpholin-2-ones. A Resolution of dl-(Secondary-alkyl)amines
-
The alcoholysis of morpholin-2-ones yielded an equilibrium mixture of morpholin-2-one and the corresponding hydroxy ester.The equilibrium constants for the methanolysis of several sustituted morpholin-2-ones were determined.Treatment of optically active morpholin-2-ones with (secondary-alkyl)amines resulted in stereoselective ring opening to afford hydroxy amides with up to 30percent de.Hydrolysis of one such hydroxy amide regenerated the optically active (secondary-alkyl)amine and the morpholin-2-one.
- Kashima, Choji,Harada, Kazuo
-
p. 789 - 792
(2007/10/02)
-
- Cycloacetals
-
New polycyclic acetals of the formula STR1 in which R1 represents an optionally substituted alkyl, cycloalkyl, aralkyl, aryl or heteroaryl radical and R2, R3, R4 and R5 independently of one another denote hydrogen or an optionally substituted alkyl, cycloalkyl, aralkyl or aryl radical, or R3 and R4 together form an optionally substituted C2 -C6 -alkylene radical or R2, R3, R4 and R5 together form a fused, optionally substituted 1,2-phenylene radical, a process for their preparation and their use for the preparation of azalactones.
- -
-
-
- Ruthenium-Catalyzed Oxidative Transformation of Alcohols and Aldehydes to Esters and Lactones
-
Primary alcohols undergo oxidative condensation upon treatment with RuH2(PPh3)4 catalyst to give esters and molecular hydrogen.Similarly, 1,4- and 1,5-diols can be converted into the corresponding γ- and δ-lactones, respectively.The lactonization is greatly enhanced by accepting hydrogen with an appropriate hydrogen acceptor such as acetone.Primary alcohols are oxidized chemoselectively in the presence of secondary alcohols to give the corresponding lactones.These reactions are operationally simple and highly efficient for synthesis of esters and lactones from alcohols.The principle of the oxidative condensation of alcohols can be extended to ester formation from aldehydes and alcohols.The ruthenium-catalyzed reaction of aldehydes with water gives esters, while the same reaction in the presence of a hydrogen acceptor gives carboxylic acids.The key step of these reactions is the oxidative addition of ruthenium into the OH bonds of alcohols and subsequent β-elimination of (RuH) species to give the corresponding carbonyl compounds.
- Murahashi, Shun-Ichi,Naota, Takeshi,Ito, Keiichiro,Maeda, Yoshihiro,Taki, Hiroshi
-
p. 4319 - 4327
(2007/10/02)
-
- REACTION DU GLYOXAL AVEC UN N-ALKYLAMINO-2 ETHANOL
-
A reinvestigation of the reaction of glyoxal with 2-(N-alkylamino)ethanol failed to yield the products previously reported, but led selectively to a condensed 2,3,5,6-dioxazinodioxane 3 and to an heterodecalin 4; crystal structures have been established b
- Rouzic, Arlette Le,Raphalen, Desire,Papillon, Denise,Kerfanto, Michel
-
p. 1853 - 1856
(2007/10/02)
-