1212-53-9Relevant articles and documents
A highly efficient flow reactor process for the synthesis of N-Boc-3,4-dehydro-l-proline methyl ester
Tamborini, Lucia,Conti, Paola,Pinto, Andrea,Micheli, Carlo De
, p. 222 - 225 (2010)
The multi-step preparation of N-Boc-3,4-dehydro-l-proline methyl ester using a modular flow reactor is reported. The use of immobilised reagents and scavengers in pre-packed glass tubes allows us to obtain the pure product in 87% overall yield, 97% purity, and >98% enantiomeric excess without any additional purification step. Our flow-based protocol enables the rapid multi-gram synthesis (about 9 g/12 h) of the desired product.
Synthesis of acylhydrazino-peptomers, a new class of peptidomimetics, by consecutive Ugi and hydrazino-Ugi reactions
Barreto, Angélica De Fátima S.,Dos Santos, Veronica Alves,Andrade, Carlos Kleber Z.
, p. 2865 - 2872 (2016)
Herein we describe a versatile approach for the synthesis of acylhydrazino-peptomers, a new class of peptidomimetics. The key idea in this approach is based on a simple route using a one-pot hydrazino-Ugi four-component reaction followed by a hydrazinolysis or hydrolysis reaction and subsequent hydrazino-Ugi reaction or classical Ugi reaction for the construction of acyclic acylhydrazino-peptomers. The consecutive multicomponent reactions produced a variety of acylhydrazino-peptomers in moderate to excellent yields (47-90%). These compounds are multifunctional intermediates that can be further functionalized to obtain new peptidomimetics with potential biological activity.
Electrochemical Dimethyl Sulfide-Mediated Esterification of Amino Acids
Li, Yongli,Wang, Huamin,Zhang, Heng,Lei, Aiwen
supporting information, p. 3023 - 3028 (2021/08/30)
Dimethyl sulfide-mediated electrochemical synthetic strategy for esterification of amino acids has been reported. A series of amino acids could react smoothly with alcohols, affording the desired esterification products with good efficiency. Importantly, the tolerance of peptides and gram-scale synthesis shed light on the utility of this protocol. Mechanistically, the dimethyl sulfide as a mediator plays an essential role in the transformation of amino acids.
Preparation method of carboxylic ester compound
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Paragraph 0042-0043, (2021/03/30)
The invention relates to a preparation method of a carboxylic ester compound, which comprises the following steps: reacting carboxylic acid with methanol in air under the catalysis of nitrite to obtain an ester compound, the preparation method disclosed by the invention has the advantages of rich raw material sources, cheap and easily available catalyst, mild reaction conditions, simplicity and convenience in operation and the like, a series of fatty carboxylic acids can be modified with high yield, and particularly, the traditional esterification method is generally not suitable for esterification of drug molecules. By utilizing the method, a series of known drug molecules can be modified, so that a shortcut is provided for discovering new drug molecules.
Green Esterification of Carboxylic Acids Promoted by tert-Butyl Nitrite
Cheng, Xionglve,Jiang, Gangzhong,Li, Xingxing,Tao, Suyan,Wan, Xiaobing,Zhao, Yanwei,Zheng, Yonggao
supporting information, p. 2713 - 2718 (2021/06/25)
In this work, the green esterification of carboxylic acids promoted by tert-butyl nitrite has been well developed. This transformation is compatible with a broad range of substrates and exhibits excellent functional group tolerance. Various drugs and substituted amino acids are applicable to this reaction under near neutral conditions, with good to excellent yields.
N-Alkenylation of hydroxamic acid derivatives with ethynyl benziodoxolone to synthesizecis-enamides through vinyl benziodoxolones
Shimbo, Daisuke,Maruyama, Toshifumi,Tada, Norihiro,Itoh, Akichika
supporting information, p. 2442 - 2447 (2021/04/02)
The stereoselective synthesis ofcis-β-N-alkoxyamidevinyl benziodoxolones (cis-β-N-RO-amide-VBXs) fromO-alkyl hydroxamic acids in the presence of an ethynyl benziodoxolone-acetonitrile complex (EBX-MeCN) is reported herein. The reaction was performed under mild conditions including an aqueous solvent, a mild base, and room temperature. The reaction tolerated variousO-alkyl hydroxamic acids derived from carboxylic acids, such as amino acids, pharmaceuticals, and natural products. Vinyl dideuteratedcis-β-N-MeO-amide-VBXs were also synthesized using deuterium oxide as the deuterium source. Valine-derivedcis-β-N-MeO-amide-VBX was stereospecifically derivatized to hydroxamic acid-derivedcis-enamides without the loss of stereoselectivity or reduction in the deuterium/hydrogen ratio.
An efficient, stereocontrolled and versatile synthetic route to bicyclic partially saturated privileged scaffolds
Bond, Andrew D.,Hanby, Abigail R.,King, Thomas A.,Moss, Thomas A.,Sore, Hannah F.,Spring, David R.,Stewart, Hannah L.
supporting information, p. 6818 - 6821 (2020/07/04)
Herein, we describe the development of a simple, high yielding and stereocontrolled strategy for the synthesis of a series of triazolopiperazines and other biologically relevant fused scaffolds from optically active amino acids. This route was applied to the synthesis of 22 scaffolds containing new, previously inaccessible vectors and used to access a novel analogue of ganaplacide.
Selective conversion of primary amides to esters promoted by KHSO4
Sattenapally, Narsimha,Sharma, Jhanvi,Hou, Yuqing
, p. 174 - 183 (2018/09/10)
Primary amides, either aliphatic or aromatic, are easily converted to the corresponding esters via reflux in lower primary alcohols in the presence of KHSO4. Secondary amides lead to complicated mixtures under analogous conditions, whereastertiary amides were inert. Use of isopropyl alcohol resulted inthe formation of product atslower rate and lower yieldalong withside products, whereas, use of tertiary alcoholsdid not give successful conversion andallyl and benzyl alcohol provided complex mixtures.
Consecutive hydrazino-Ugi-azide reactions: Synthesis of acylhydrazines bearing 1,5-disubstituted tetrazoles
De Fátima Barreto, Angélica S.,Dos Santos, Veronica Alves,Zandrade, Carlos Kleber
, p. 2596 - 2602 (2018/01/17)
Isocyanide-based multicomponent reactions (IMCRs) allow the construction of relatively complex molecules through a one-pot synthesis. The combination of IMCRs in a consecutive or sequential fashion further extends the complexity of the molecules obtained. Herein, we report the efficient application of this approach to the synthesis of acylhydrazines bearing 1,5-disubstituted tetrazoles. Our strategy was accomplished in only three steps: first, a one-pot hydrazino-Ugi-azide four-component reaction; second a hydrazinolysis and finally an additional hydrazino-Ugi-azide reaction. This sequence provides the title compounds in moderate to excellent yields. The products synthesized herein contain functional groups within their structures that can be easily modified to obtain new acylhydrazino 1,5-disubstituted tetrazoles.
A Simple, efficient, Catalyst-Free and Solvent-Less Microwave-Assisted process for N-Cbz Protection of Several amines
Aouf, Zineb,Mansouri, Rachida,Lakrout, Salah,Berredjem, Malika,Aouf, Nour-Eddine
, p. 151 - 156 (2017/08/02)
A simple, green and chemo-selective method for the N-benzyloxycarbonylation of amines, β-amino alcohols, α-amino esters and sulfonamides has been developed under microwave irradiation. Good to excellent yields of the N-benzyloxy-carbamates compounds were obtained in short times without any side products.
