- C-H Amination via Electrophotocatalytic Ritter-Type Reaction
-
A method for C-H bond amination via an electrophotocatalytic Ritter-Type reaction is described. The reaction is catalyzed by a trisaminocyclopropenium (TAC) ion in an electrochemical cell under irradiation. These conditions convert benzylic C-H bonds to acetamides without the use of a stoichiometric chemical oxidant. A range of functionality is shown to be compatible with this transformation, and several complex substrates are demonstrated.
- Lambert, Tristan H.,Shen, Tao
-
-
Read Online
- Enantioselective acylation of chiral amines catalysed by aminoacylase I
-
Aminoacylase (E.C. 3.5.1.14) from Aspergillus melleus mediated the acylation of the primary amino group in a range of primary arylalkylamines and amino alcohols in anhydrous organic medium. The commonly used vinyl and isopropenyl esters proved to be unsuitable acyl donors because rapid uncatalysed aminolysis occurred in the presence of these additives. The unwanted aminolysis reaction could be suppressed by performing the enzymatic reaction in tert-butyl methyl ether medium with methyl 2-methoxyacetate as the acyl donor. We found that chiral amines were acylated with poor to moderate enantioselectivity, in contrast with the quantitative enantiodiscrimination that is commonly observed with the corresponding alcohols.
- Youshko, Maxim I,Van Rantwijk, Fred,Sheldon, Roger A
-
-
Read Online
- Carbonic anhydrase inhibitors. Design of anticonvulsant sulfonamides incorporating indane moieties
-
A series of aromatic sulfonamides incorporating indane moieties were prepared starting from commercially available 1- and 2-indanamine, and their activity as inhibitors of two carbonic anhydrase (CA, EC 4.2.1.1) isozymes, hCA I and II was studied. The new sulfonamides incorporating acetamido, 4-chloro-benzoyl, valproyl, tetra-, and pentafluorobenzoyl moieties acted as very potent inhibitors of the slow red blood cell isozyme hCA I (Kis in the range of 1.6-8.5 nM), which usually has a lower affinity for such inhibitors, as compared to isozyme II. Some derivatives also showed excellent hCA II inhibitory properties (Kis in the range of 2.3-12 nM), but the anticonvulsant activity of these sulfonamides was rather low as compared to that of other sulfonamide/sulfamate CA inhibitors, such as methazolamide. Furthermore, the 2-amino/acetamido-indane-5-sulfonic acids prepared during this work also showed interesting CA inhibitory properties, with inhibition constants in the range of 43-89 nM against the two isozymes, being among the most potent sulfonic acid CA inhibitors reported so far.
- Chazalette, Celine,Masereel, Bernard,Rolin, Stéphanie,Thiry, Anne,Scozzafava, Andrea,Innocenti, Alessio,Supuran, Claudiu T.
-
-
Read Online
- Biocatalytic, Intermolecular C?H Bond Functionalization for the Synthesis of Enantioenriched Amides
-
Directed evolution of heme proteins has opened access to new-to-nature enzymatic activity that can be harnessed to tackle synthetic challenges. Among these, reactions resulting from active site iron-nitrenoid intermediates present a powerful strategy to forge C?N bonds with high site- and stereoselectivity. Here we report a biocatalytic, intermolecular benzylic C?H amidation reaction operating at mild and scalable conditions. With hydroxamate esters as nitrene precursors, feedstock aromatic compounds can be converted to chiral amides with excellent enantioselectivity (up to >99 % ee) and high yields (up to 87 %). Kinetic and computational analysis of the enzymatic reaction reveals rate-determining nitrenoid formation followed by stepwise hydrogen atom transfer-mediated C?H functionalization.
- Arnold, Frances H.,Athavale, Soumitra V.,Gao, Shilong,Hirschi, Jennifer S.,Liu, Zhen,Mallojjala, Sharath Chandra
-
supporting information
p. 24864 - 24869
(2021/10/15)
-
- Method for preparing amide from aryl methane derivative and nitrile
-
The invention provides a simple and efficient method for directly preparing an amide compound from an aryl methane derivative and nitrile. In the method, manganese triacetate dihydrate is used as a catalyst, and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone(DDQ) is used as an oxidizing agent. The method has the characteristics that raw materials are cheap and easy to obtain, the source of the nitrile is wide, reaction conditions are mild, the applicability is wide and the like. The method solves the problems that ceric ammonium nitrate (CAN) and a fluorine agent which are used by a method for directly synthesizing amide by using aryl methane and nitrile compounds are hard to treat, atomic economy is poor, the source of the nitrile is narrow and the like.
- -
-
Paragraph 0032-0034
(2017/05/10)
-
- Manganese(III) acetate catalyzed oxidative amination of benzylic C(sp3)-H bonds with nitriles
-
Mn-Catalyzed oxidative amination of benzylic C(sp3)-H bonds with nitriles is disclosed, which enables the synthesis of a broad range of secondary amides in moderate to excellent yields under mild conditions. The interaction between Mn(iii) and DDQ facilitates the oxidation and makes it highly efficient and selective.
- Zhang, Yaxing,Dong, Jianyu,Liu, Lixin,Liu, Long,Zhou, Yongbo,Yin, Shuang-Feng
-
supporting information
p. 2897 - 2901
(2017/04/11)
-
- HBF4·OEt2 as a mild and versatile reagent for the Ritter amidation of olefins: A facile synthesis of secondary amides
-
A variety of alkenes undergo smooth amidation with nitriles in the presence of HBF4·OEt2 at room temperature under mild conditions to afford the corresponding secondary amides in good to excellent yields. This is a highly efficient method for the preparation of α-aryl ethyl amides especially from vinyl arenes without any side reactions such as olefin polymerization. The use of readily available and easy to handle reagent HBF4·OEt2 makes this method simple, convenient, and practical.
- Subba Reddy,Sivasankar Reddy,Madan, Ch.,Yadav
-
experimental part
p. 4827 - 4829
(2010/10/02)
-
- Synthesis of enamides via Rh/C-catalyzed direct hydroacylation of ketoximes
-
(Chemical Equation Presented) Enamides were efficiently prepared via a novel Rh/C-catalyzed direct hydroacylation of ketoximes. Up to 88% isolated yield of enamides were obtained with this method. Subsequent asymmetric hydrogenation of the enamides with Rh/DuanPhos complex gave the corresponding chiral amine in excellent enantioselectivities (up to 99.7% ee).
- Guan, Zheng-Hui,Huang, Kexuan,Yu, Shichao,Zhang, Xumu
-
scheme or table
p. 481 - 483
(2009/07/18)
-
- Indanesulfonamides as carbonic anhydrase inhibitors. Toward structure-based design of selective inhibitors of the tumor-associated isozyme CA IX
-
Carbonic anhydrases are ubiquitous metalloenzymes which are involved in fundamental processes (i.e., acid-base regulation, respiration, calcification, etc.). The carbonic anhydrase isozyme IX becomes an interesting pharmacological target due to its overexpression in cancer and its absence in normal tissue. Therefore, several indanesulfonamides were synthesized and tested for their inhibition both against the human CA IX and against two other biologically relevant isozymes (CA I and II). Structure-activity relationships are discussed and point out different compounds for its selectivity and activity against CA IX. To establish preliminary hypothesis for the design of new isozyme-selective CA IX inhibitors, we conducted molecular modeling. We describe here the first human CA IX model built by homology with another CA isozyme already crystallized. Docking studies were performed to explore the binding mode of our indanesulfonamide derivatives.
- Thiry, Anne,Ledecq, Marie,Cecchi, Alessandro,Dogné, Jean-Michel,Wouters, Johan,Supuran, Claudiu T.,Masereel, Bernard
-
p. 2743 - 2749
(2007/10/03)
-
- TiO2-sensitised photo-oxidation mechanism of indane and some of its hetero-analogues in deaerated CH3CN
-
A mechanistic study, principally based on product analysis, relative to the TiO2-photosensitized oxidation of indane and some of its hetero-analogues, in deaerated CH3CN and in the presence of Ag 2SO4, was performed. In particular: (i) 1-acetamidoindan (principal product), indene, 1-indanol and 1-indanone were obtained from indan; (ii) 5-methoxyindan gave 6-methoxyindene (principal product) and 5-methoxy-1-indanone; (iii) 2,3-dihydrobenzofuran, 2,3-dihydroindole and 2,3-dihydrobenzothiophene produced benzofuran, indole and benzothiophen (the last one accompanied by minor amounts of 2,3-dihydrobenzothiophene-1-oxide), respectively. Considering the previous studies on photo-oxidation of analogous substrates as benzylic derivatives (arenes, alcohols and ethers) and from reaction product profiles, an electron-transfer mechanism (from the substrate to the photogenerated hole) is suggested, where the radical cation intermediate should deprotonate to a benzylic radical. The carbocation obtained from the oxidation of this radical should competitively evolve to alkene, alcohol and acetamide. H218O labelling photo-oxidation experiments suggest that the ketone, when present, should derive from the substrate, through the alcohol as intermediate. Copyright
- Bettoni, Marta,Giacco, Tiziana Del,Rol, Cesare,Sebastiani, Giovanni V.
-
p. 359 - 364
(2007/10/03)
-
- A convenient protocol for C-H oxidation mediated by an azido radical culminating in Ritter-type amidation
-
Cerium(IV) ammonium nitrate in combination with sodium azide reacts with unactivated hydrocarbons in acetonitrile to furnish acetamides in one pot. The strategy can be used to introduce nitrogen functionality into a variety of compounds; a carboxylic ester directly afforded the corresponding α-amino acid.
- Nair, Vijay,Suja,Mohanan, Kishor
-
p. 3217 - 3219
(2007/10/03)
-