- Organotin-catalyzed synthesis of hydroxyalkylamides from lactones via a ring-opening process
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A new strategy for the facile synthesis of hydroxyalkylamides through the ring-opening reaction of lactone with amine promoted by dibutyltin acetate was developed. A series of hydroxyalkylamide compounds were obtained and the method was successfully applied to the synthesis of pharmaceutically active molecules tyrosinase inhibitor V and HDAC inhibitor VI via a three-step synthetic pathway. The broad substrate scope, mild reaction conditions and practical application proved the effectiveness, compatibility and practicality of this method.
- Liang, Xiayu,Yu, Peng,Fu, Chen,Shen, Yongcun
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supporting information
(2021/02/09)
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- CATALYST FOR CONVERTING ESTER TO AMIDE USING HYDROXYL GROUP AS ORIENTATION GROUP
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Provided is a method for amidating a hydroxy ester compound at a high chemical selectivity. The amidation reaction method for a hydroxy ester compound comprises, in the presence of a catalyst containing a compound of a transition metal of the group 4 or group 5 in the periodic table, reacting at least one kind of hydroxy ester compound selected from the group consisting of an α-hydroxy ester compound, a β-hydroxy ester compound, a γ-hydroxy ester compound and a δ-hydroxy ester compound with an amino compound so as to amidate an ester group having a hydroxyl group at the α-, β-, γ- or δ-position of the hydroxy ester compound.
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Paragraph 0059; 0072-0073
(2021/03/13)
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- Preparation method of hydroxyamide
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The invention discloses a preparation method of a hydroxyamide shown as formula (I). The hydroxyamide is prepared through homogeneous catalytic hydrogenation reaction of a cyclic imide represented byformula (II), wherein R1, R2 and R3 are respectively and
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Paragraph 0076-0079
(2020/02/10)
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- Zirconium-catalyzed direct amide bond formation between carboxylic esters and amines
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Development of catalytic amide bond formation reactions from readily available starting materials remains a challenging task for modern organic chemistry. Herein, we report that unactivated carboxylic esters and amines react in the presence of 10 mol % of zirconocene dichloride (Cp2ZrCl2) in toluene at 110 °C to afford amides in very good to excellent conversions. The Zr-catalyzed reaction is amenable for the amidation of aliphatic and aromatic carboxylic esters with primary and secondary amines. The reaction proceeds with almost complete retention of configuration for chiral esters and chiral amines.
- Lenstra, Danny C.,Nguyen, D. Thao,Mecinovi?, Jasmin
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p. 5547 - 5553
(2015/08/03)
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- Chemoselective calcium-catalysed direct amidation of carboxylic esters
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Unactivated carboxylic esters and primary amines undergo calcium-catalysed direct amide bond formation in excellent yields under homogeneous conditions in toluene. This green and mild reaction proceeds chemoselectively with esters, whereas related carboxylic acids and amides remain unreactive.
- Nguyen, D. Thao,Lenstra, Danny C.,Mecinovi?, Jasmin
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p. 77658 - 77661
(2015/09/28)
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- Microwave-promoted direct amidation of unactivated esters catalyzed by heteropolyanion-based ionic liquids under solvent-free conditions
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Abstract A simple and efficient procedure for the synthesis of amides directly from unactivated esters and amines catalyzed by heteropolyanion-based ionic liquids under microwave-promoted and solvent-free conditions has been reported. The practical protocol was found to be compatible with different structurally diverse substrates. Moderate to excellent yields, solvent-free media, and operational simplicity are the main highlights. Furthermore, the heteropolyanion-based ionic liquids were easily reusable for this amidation.
- Fu, Renzhong,Yang, Yang,Ma, Yunsheng,Yang, Fei,Li, Jingjing,Chai, Wen,Wang, Quan,Yuan, Rongxin
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supporting information
p. 4527 - 4531
(2015/06/30)
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- Reductive hydroxyalkylation/alkylation of amines with lactones/esters
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We have developed a one-pot method for the direct intermolecular reductive hydroxyalkylation or alkylation of amines using lactones or esters as the hydroxyalkylating/alkylating reagents. The method is based on the in situ amidation of lactones/esters with DIBAL-H-amine complex (for primary amines) or DIBAL-H-amine hydrochloride salt complex (for secondary amines), followed by reduction of the amides with an excess of DIBAL-H. Different from the reduction of Weinreb amides with DIBAL-H where aldehydes are formed, the reduction of the in situ formed Weinreb amides yielded amines. Moreover, this method is not limited to Weinreb amides, instead, it also works for other amides in general. A plausible mechanism is suggested to account for the outcome of the reactions.
- Wang, Yu-Huang,Ye, Jian-Liang,Wang, Ai-E,Huang, Pei-Qiang
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experimental part
p. 6504 - 6511
(2012/09/08)
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- A mild and facile synthesis of cyclic imides using pyridinium chlorochromate
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A mild and facile synthetic method of cyclic imides is presented. These compounds are widely used in the synthesis of novel medical, polymeric, photonic and electronic materials. Compared with traditional syntheses, the method reported has several advantages including mild conditions, simplified work-up and low cost.
- Yang, Yanyan,Wang, Ge,Cao, Xiaohui,Yan, Xilong,Chen, Ligong
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p. 657 - 658,2
(2020/07/30)
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- Regioselective synthesis of 1-alkyl-5-(indol-3-yl- and -2-yl)pyrrolidin-2- ones from available reagents
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The reaction under mild conditions of 1-alkyl-5-hydroxypyrrolidin-2-ones with different indoles having a free 3 position leads exclusively to 1-alkyl-5-(indol-3-yl)pyrrolidin-2-ones but if position 3 is occupied to 1-alkyl-5-(indol-2-yl)pyrrolidin-2-ones.
- Sadovoy,Kovrov,Golubeva,Sviridova
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p. 1215 - 1223
(2011/10/09)
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- Seven membered ring chelates derived from γ-hydroxyamides and triphenyltin or diphenylboron
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N-Benzyl-4-hydroxy-butyramide (1), 4-hydroxy-N-[(R)-1-phenyl-ethyl]-butyramide (2), and (R)-4-hydroxy-2-methyl-N-[(R)-1-phenyl-ethyl]-butyramide (3a) were used to prepare new diphenylboron and triphenyltinoxy compounds: diphenylborinic acid 3-benzylcarbamoyl-propyl ester (4), diphenylborinic acid 3-[(R)-1-phenyl-ethylcarbamoyl]-propyl ester (5) and diphenylborinic acid (R)-3-[(R)-1-phenyl-ethylcarbamoyl]-butyl ester (6), N-benzyl-4-triphenyltinoxy-butyramide (7), 4-triphenyltinoxy-N-[(R)-1-phenyl-ethyl]-butyramide (8), and (R)-4-triphenyltinoxy-2-methyl-N-[(R)-1-phenyl-ethyl]-butyramide (9). The X-ray diffraction analysis of a crystalline structure of the new γ-hydroxyamide 3a is reported, as well as that of the first example of a crystalline structure where a diphenylborinic ester forms a seven membered chelate, by a carbonyl coordination to boron (4). Structural studies of tin and boron esters were performed by NMR. The C{double bond, long}O internal coordination to tin atoms, affording seven membered rings, was observed by 119Sn NMR experiments at low temperature.
- Salas-Coronado, Raúl,Colorado-Peralta, Raúl,Sánchez-Ruiz, Sonia A.,Contreras, Rosalinda,Flores-Parra, Angelina
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experimental part
p. 616 - 622
(2009/05/30)
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- Acyl transfer catalysis with 1,2,4-Triazole anion
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1,2,4-Triazole anion has been identified as an active acyl transfer catalyst suitable for the aminolysis and transesterification of esters.
- Yang, Xing,Birman, Vladimir B.
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supporting information; experimental part
p. 1499 - 1502
(2009/09/06)
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- LiNTf2-catalyzed aminolysis of lactones with stoichiometric quantities of amines
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LiNTf2 in the reaction of lactones with amines is able to activate cyclic esters towards ring opening, thus leading to clean open-chain amides under mild conditions and using a stoichiometric amount of amine. The generality of the method was demonstrated by a range of selected lactones and amines. Georg Thieme Verlag Stuttgart.
- Lalli, Claudia,Trabocchi, Andrea,Menchi, Gloria,Guarna, Antonio
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p. 189 - 192
(2008/09/21)
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- Fast, acid-free, and selective lactamization of lactones in ionic liquids
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(Chemical Equation Presented) A fast and acid-free one-pot 0.2-30 mmol microwave methodology for direct ionic liquid-mediated preparation of lactams from lactones and primary amines has been developed. The protocol was investigated with a wide range of primary amines and a handful of lactones, including substrates with acid-sensitive substituents. Both γ-lactams and δ-lactams were, despite the complete absence of a Bronsted acid, obtained in useful to excellent yields after only 35 min of microwave processing.
- Orrling, Kristina M.,Wu, Xiongyu,Russo, Francesco,Larhed, Mats
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experimental part
p. 8627 - 8630
(2009/04/11)
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- A convenient aminolysis of esters catalyzed by 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) under solvent-free conditions
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Aminolysis of esters by using the organocatalyst 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) is reported. Secondary and tertiary amides were synthesized from alkyl or aryl esters with a variety of primary and secondary amines in good to excellent yields (60-94%) under solvent-free conditions (SFC).
- Sabot, Cyrille,Kumar, Kanduluru Ananda,Meunier, Stéphane,Mioskowski, Charles
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p. 3863 - 3866
(2008/02/02)
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- Chemoselective hydrogenation of imides catalyzed by Cp*Ru(PN) complexes and its application to the asymmetric synthesis of paroxetine
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This work represents the first catalytic hydrogenation of imides into amides and primary alcohols, in which the unique chemoselectivity is originated from the bifunctional nature of ruthenium-NH moiety in the catalyst. Copyright
- Ito, Masato,Sakaguchi, Ayaka,Kobayashi, Chika,Ikariya, Takao
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p. 290 - 291
(2008/04/18)
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- Stereochemical memory effects in alkene radical cation/anion contact ion pairs: Effect of substituents, and models for diastereoselectivity
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A series of 12 stereochemically defined 2,m-dimethyl- and 2,m,n-trimethyl-6-benzylamino-2-nitro-3-(diphenylphosphatoxy)hexanes have been synthesized and their cyclization reactions leading to di- and trisubstituted N-benzyl pyrrolidines examined in the presence of tributyltin hydride and azoisobutyronitrile in benzene at reflux. The cyclizations are interpreted in terms of generation of an alkyl radical by abstraction of the nitro group with a stannyl radical. The phosphate leaving group is then expelled in a heterolytic cleavage to give a contact alkene radical cation/phosphate anion pair. For the majority of the examples studied, the cyclizations are best understood in terms of nucleophilic attack by the amine on the opposite face of the alkene radical cation to the one shielded by the leaving group, within the confines of the initial contact ion pair, resulting in overall cyclization with inversion of configuration. Dependent on the relative stereochemistry of the substituents, the cyclization is envisaged as taking place through either chair-like or twist-boat-like transition states with the maximum number of substituents pseudo-equatorial. The model breaks down when cyclization on the initial contact ion pair would engender significant destabilizing steric interactions, especially 1,3A strain in the alkene radical cation. In these cases a fully equilibrated Beckwith-Houk-type transition state provides a satisfactory model. Interesting examples of matching and mismatching in the Corey-type oxazaborolidine-mediated reduction of alkyl (methyl-1-nitroethyl) ketones by a β-methyl group in the alkyl chain are reported, and the mismatching is attributed to a developing syn-pentane interaction in the transition state.
- Crich, David,Ranganathan, Krishnakumar
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p. 9924 - 9929
(2007/10/03)
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- A prodrug system for hydroxylamines based on esterase catalysis
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The synthesis and reactivity of hydroxy hydroxamates as models for a prodrug form of hydroxylamine are described. γ-Hydroxy hydroxamates were found to enable hydroxylamine release via lactonisation. Hydroxamates were found to undergo esterase catalysed hydrolysis.
- Conejo-Garcia, Ana,Schofield, Christopher J.
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p. 4004 - 4009
(2007/10/03)
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- Investigations into the mechanism of lactamization of lactones yielding in a novel route to biologically active tryptamine derivatives
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The mechanism of lactamization of corresponding lactones was investigated by means of gas chromatography and synthesis of possible intermediates as references. Lactones react with amines via the amino acid with subsequent elimination of water to the corresponding lactams. In the first step, also hydroxyamides are in equilibrium with the lactones and amines, respectively, which are not able to form the amide though. This mechanism opens a new approach for the synthesis of Nβ-disubstituted tryptamines.
- Decker, Michael,Nguyen, Thi Thanh Huyen,Lehmann, Jochen
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p. 4567 - 4578
(2007/10/03)
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- DIBAL-H-H2NR and DIBAL-H-HNR1R2·HCl complexes for efficient conversion of lactones and esters to amides
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The reaction of a lactone or an ester with organoaluminum species generated from DIBAL-H-H2NR or DIBAL-H-HNR1R2·HCl complexes provided efficient methods for preparation of amides. Conditions were defined for the preparation of both secondary and tertiary amides, including Weinreb amides in excellent yields.
- Huang, Pei-Qiang,Zheng, Xiao,Deng, Xian-Ming
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p. 9039 - 9041
(2007/10/03)
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