- Synthesis of new amides based on N-Phthaloyl-α-Amino Acids
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N-phthaloyl derivatives of aliphatic α-amino acids were synthesized using phthalanhydride under standard conditions. The optimization reaction carried out by the thermal method to obtain the amides of these N-phthaloyl amino acids resulted in transimitted rather than amidation. The target amides of N-phthaloyl-α-amino acids were obtained by acylation of the amine with the corresponding acid chloroanhydrides in dichloromethane. These results were compared with the results of a similar acylation in a non-polar solvent (benzene). The dependence of the direction of the reaction on the duration of the acylation and the amount of amine used was established. The conditions for the formation of the corresponding N-phthaloyl-α-amino acid amides and asymmetric phthalic acid diamides were found. It is noteworthy that the formation of diamides is directly proportional to the equivalent amount of amine and the duration of the reaction, which makes it possible to purposefully control the synthesis in one reactor.
- Tukhtaev,Yusupov,Vinogradova
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p. 3049 - 3058
(2021/05/28)
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- AMINO ACID DERIVATIVES FOR THE TREATMENT OF INFLAMMATORY DISEASES
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The present disclosure provides certain amino acid derivatives that inhibit NF-kB activation and are therefore useful for the treatment of inflammatory diseases. Also provided are pharmaceutical compositions containing such compounds and processes for preparing such compounds.
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- Synthesis of novel phthalimido oxime pseudoesters and evaluation of their cytotoxicity
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A series of novel optically pure oxime pseudoesters derivatives were synthesized by the reaction of substitute keto oximes with various N-substituted α-amino acids chlorides in the presence of triethylamine and dichloromethane at 0 °C, and their structures were characterized by IR and 1D-NMR methods. The synthesized compounds were tested for their ability to inhibit the proliferation of human colon cancer cells and human epithelial cells. Some of them were revealed to have a significant cytotoxic effect.
- Mehrez, Asma,Chakroun, Ibtissem,Mtat, Dalila,Mansour, Hédi Ben,Touati, Ridha
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- A Simple Aliphatic Diamine Auxiliary for Palladium-Catalyzed Arylation of Unactivated β-C(sp3)-H Bonds
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Palladium-catalyzed β-C(sp3)-H arylation of aliphatic acid derivatives was achieved by means of 2-dimethylaminoethylamine auxiliary as a directing group. The β-C(sp3)-H arylation reactions with aryl and heteroaryl iodides efficiently afforded the corresponding arylated hydrocinnamic acid derivatives. Direct β-C(sp3)-H alkynylation, and arene C?H arylation and alkynylation were also realized under the same or slightly modified conditions. The aliphatic diamine auxiliary in the products could be readily removed by methanol in the presence of BF3 ? OEt2. In comparison with the widely used bidentate nitrogen-containing directing groups, 2-dimethylaminoethylamine is a simple, cheap, readily available and removable, and atom-economical directing group for C?H functionalization. (Figure presented.).
- Lou, Jiang,Wang, Quannan,He, Yuan,Yu, Zhengkun
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p. 4571 - 4584
(2018/10/25)
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- 1,2-Hydride Migration in Dialkyl α-Diazophosphonates Catalyzed by [Cu(MeCN)4]PF6: A Novel Approach to β-Amino (E)-Enylphosphonates
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The regiospecific and stereoselective 1,2-migration reaction of dialkyl α-diazophosphonates for the synthesis of β-amino (E)-enylphosphonates is developed utilizing tetrakis(acetonitrile)copper(I) hexafluorophosphate [Cu(MeCN)4PF6] as the catalyst and N,N-dimethylformamide as an additive. A possible mechanism for the 1,2-migration reaction involving a metal carbene is presented. An investigation on the E/Z isomer selectivity of this process demonstrates that steric factors play an important role on the outcome. This process provides a straightforward access to β-amino (E)-enylphosphonates in moderate to good yields.
- Ge, Haihong,Liu, Shuang,Cai, Yan,Sun, Yuchao,Miao, Zhiwei
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p. 448 - 454
(2016/01/28)
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- Development of modifiable bidentate amino oxazoline directing group for Pd-catalyzed arylation of secondary C-H bonds
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Abstract A novel bidentate α-amino oxazolinyl directing group has been developed. Different from previous directing groups, this newly designed directing group was easily prepared from amino acids and modified in structure. This auxiliary preferentially effects functionalization at secondary C(sp3)-H bonds, rather than at aryl C(sp2)-H bonds. The diastereoselectivity of direct arylation between geminal secondary C(sp3)-H bonds in linear molecules has also been realized for the first time with a chiral directing group by remote chirality relay. Two diastereoisomers are produced with the same chiral source by changing the substituents of substrates and aryl halides. A new direction: A multifunctional amino oxazoline directing group that is readily available from amino acids, has been developed, which can induce chemo-, regio- and diastereoselectivity in secondary C(sp3)-H arylation reactions. Furthermore, this directing group is removable and modifiable. Steric control and counterions play important roles in the relayed chirality transfer.
- Chen, Kang,Li, Zhao-Wei,Shen, Peng-Xiang,Zhao, Hong-Wei,Shi, Zhang-Jie
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p. 7389 - 7393
(2015/05/13)
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- Pd(II)-catalyzed C(sp3)-H arylation of amino acid derivatives with click-triazoles as removable directing groups
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By using click-triazoles as conveniently approachable and removable directing groups, the direct palladium-catalyzed C(sp3)-H arylation of amino acid derivatives with various aryl iodides bearing different electronic properties has been achieved. Notably, the desired amino acid molecule can be obtained by the cleavage of the tethered click-triazoles after the catalytic reaction, which aims to provide a practical protocol for the accessibility of both natural and synthetic amino acids.
- Zhang, Guofu,Xie, Xiaoqiang,Zhu, Jianfei,Li, Shasha,Ding, Chengrong,Ding, Ping
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p. 5444 - 5449
(2015/05/20)
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- Trifluoroborane-catalyzed C-H functionalization/S-H insertion reaction: Construction of N,S-acetal quaternary centers
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Abstract The trifluoroborane-catalyzed C-H functionalization/S-H insertion reaction of α-diazophosphonates with thiols has been developed. A plausible reaction mechanism has been proposed to understand the combined reaction. This process provides straightforward access to N,S-acetals containing quaternary centers in moderate to good yields and chemoselectivity.
- Cai, Yan,Ge, Haihong,Sun, Weize,Miao, Zhiwei
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p. 1669 - 1677
(2015/06/02)
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- Silicon-containing poly(esters) with halogenated bulky side groups. Synthesis, characterization and thermal studies
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Poly(esters) (PEs) derived from diacids containing bulky side groups, which have an halogenated (Cl, Br) imide ring, an aminoacidic residue (glycine, l-alanine, l-valine) and an amide group were obtained with a silicon-containing diphenol. Also PEs without the aminoacidic residue were obtained. PEs were characterized by IR and NMR spectroscopy, and the results were in agreement with the proposed structures. PEs were obtained with good yields and moderate or high ηinh values. PEs were soluble in aprotic polar solvents and were swollen in other solvents like m-cresol and THF. The Tg values were determined and it was possible to see a tendency in the sense that when the size of the atom (Cl, Br) bonded to the imidic ring is increased, the Tg values decreased, also for those PEs obtained without the aminoacidic residue. The thermal decomposition temperatures showed that only two PEs can be considered as thermostable, considering TDT values above 400°C at 10% of weight lost. The other PEs showed good thermal stability, showing in general a decrease of the TDT values when the volume of the side group, is increased. PEs showed UV-vis transparency at 400 nm lower than 20%, but between 500 and 600 nm, showed 80% transparency. PEs containing halogen atoms showed flame retardancy in a simple essay, with respect to PEs without halogen atoms in which the combustion was complete.
- Tagle,Terraza,Tundidor-Camba,Coll
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p. 49132 - 49142
(2015/06/16)
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- LIGAND-CONTROLLED C(SP3)-H ARYLATION AND OLEFINATION IN SYNTHESIS OF UNNATURAL CHIRAL ALPHA AMINO ACIDS
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The use of ligands to tune the reactivity and selectivity of transition metal-catalysts for C(-sp3)-H bond functionalization is a central challenge in synthetic organic chemistry. Herein, we report a rare example of catalyst-controlled C(sp3)-H arylation using pyridine and quinoline derivatives: the former promotes exclusive monoarylation, whereas the latter activates the catalyst further to achieve diarylation. Successive application of these ligands enables the sequential diarylation of a methyl group in an alanine derivative with two different aryl iodides, affording a wide range of β-Ar-p-Ar ' -cc-amino acids with excellent levels of diastereoselectivity (d.r. > 20:1). Both configurations of the β-chiral center can be accessed by choosing the order in which the aryl groups are installed. The use of a quinoline derivative as a ligand also enables C(sp3)-H olefination of a protected alanine.
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- Chiral Pool-Based Synthesis of Naphtho-Fused Isocoumarins
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A variety of chiral derivatives of benzo[d]naphtho[1,2-b]pyran-6-one were prepared in a single step by Et3N-mediated condensation of homophthalic anhydride with different derivatives of (S)-amino acid chlorides at -5 °C by employing a chiral pool methodology. Chirality 27:951-957, 2015.
- Raza, Abdul Rauf,Saddiqa, Aisha,?akmak, Osman
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p. 951 - 957
(2015/11/16)
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- Unexpected stereoselective synthesis of (Z)-β-alkenyl substituted β-amino phosphonates through β,γ-dihydrogen shift reaction catalyzed by a copper(I) complex and iodine [Cu(MeCN)4]PF 6/I2
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A series of dialkyl a-diazophosphonates has been prepared from natural amino acids. The diazo decomposition of these diazophosphonate compounds with tetrakis(acetonitrile)copper(I) hexafluorophosphate/iodine, [Cu(MeCN) 4]PF6/I2, as catalyst has been investigated. It was found that the diazo decomposition of dialkyl a-diazophosphonates gave a mixture of β,γ-dihydrogen shift and 1,2-hydride migration products and afforded β-alk- enyl-substituted β-amino phosphonates with the Z configuration. The mechanism of this novel diazo decomposition process was discussed.
- Cai, Yan,Lyu, Hairong,Yu, Chengbin,Miao, Zhiwei
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p. 596 - 602
(2014/05/20)
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- Chiron based synthesis of isocoumarins: Reactivity of α-substituted carboxylic acids
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The asymmetric synthesis of a novel (S)-isocoumarin has been attempted in a single step by the coupling of homophthalic acid with (S)-N-protected amino acids and α-chloroacids at high temperature by exploiting a chiral pool methodology. The coupling of homophthalic acid with N-protected (S)-amino acids gave exclusion of the carboxyl/alkyl group. However, coupling of homophthalic acid with α-chloroacids afforded asymmetric isocoumarins in high yield.
- Saddiqa, Aisha,Raza, Abdul R.,Black, David Stc.,Kumar, Naresh
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p. 736 - 743
(2014/06/09)
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- Combined C-H functionalization/O-H insertion reaction to form tertiary β-alkoxy substituted β-aminophosphonates catalyzed by [Cu(MeCN) 4]PF6
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The copper-catalyzed C-H functionalization/O-H insertion reaction of α-diazophosphonates with alcohols has been developed with iodine as an additive. In order to understand this reaction, we present here a possible mechanism for the combined reaction. This process provides straightforward access to tertiary β-alkoxy substituted β-aminophosphonate derivatives with moderate to good yields. The Royal Society of Chemistry.
- Cai, Yan,Lu, Yuchen,Yu, Chengbin,Lyu, Hairong,Miao, Zhiwei
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p. 5491 - 5499
(2013/09/02)
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- Use of a readily removable auxiliary group for the synthesis of pyrrolidones by the palladium-catalyzed intramolecular amination of unactivated γ C(sp3)-H Bonds
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Easy on, easy off: Directing groups found to promote the palladium-catalyzed amination of γ C(sp3)-H and C(sp 2)-H bonds of secondary amides included 5-methoxy-8-aminoquinoline, which can be removed under mild conditions (see scheme; CAN=ceric ammonium nitrate). In conjunction with a β-C-H methylation or γ-C-H arylation step, the γ-C(sp3)-H amination provided access to complex pyrrolidones from readily available precursors. Copyright
- He, Gang,Zhang, Shu-Yu,Nack, William A.,Li, Qiong,Chen, Gong
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p. 11124 - 11128
(2013/10/22)
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- Nonnatural amino acid synthesis by using carbon-hydrogen bond functionalization methodology
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Taking direction well: Substituted phenylalanine derivatives were prepared by C-H bond functionalization (see scheme). The syntheses are highly convergent and employ an N-phthaloylalanine with a 2-thiomethylaniline directing group. The use of an 8-aminoquinoline directing group allows for the diarylation of methyl and the diastereoselective arylation of methylene groups. Copyright
- Tran, Ly Dieu,Daugulis, Olafs
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p. 5188 - 5191
(2012/07/27)
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- Acylative kinetic resolution of racemic heterocyclic amines using N-phthaloyl-(S)-amino acyl chlorides with alkyl side chains
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A comparative study of the acylative kinetic resolution of racemic 2-methyl-1,2,3,4 tetrahydroquinoline and 3,4-dihydro-3-methyl-2H-[1,4] benzoxazine using N-phthaloyl-(S)-amino acyl chlorides with alkyl side chains has been carried out. The influence of steric factors on the stereoselectivity of the acylation was demonstrated. The (S)-enantiomers of the heterocyclic amines (ee >99%) were obtained in good yields via a kinetic resolution protocol using N-phthaloyl-(S)-leucyl chloride.
- Gruzdev, Dmitry A.,Levit, Galina L.,Krasnov, Victor P.
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p. 1640 - 1646
(2013/02/23)
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- Substituted Phenylpiperazinyl Aralkylalcohol Derivatives, Pharmaceutical Compositions Containing Such Derivatives and Uses Thereof
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The invention relates to a substituted phenylpiperazine aryl alkanol derivative represented by the following general formula and its salt and hydrate, wherein C1 and C2 represent chiral carbon atoms, and the compound is one of the six isomers: (1RS, 2SR), (1RS, 2RS), (1R, 2S), (1S, 2S), (1R, 2R) or (1S, 2R); and R, R1, R2, R3 and Ar are as defined in the specification. The derivative is non-opioid analgesic, has good analgesic effect and relatively small side effects. The invention also relates to a composition comprising the derivative and its use.
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- SULFUR YLIDES. 3. SYNTHESIS OF KETO-GROUP STABILIZED AMINO-CONTAINING SULFUR YLIDES FROM AMINO ACIDS
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An effective path of synthesis was developed of new synthetic intermediates, the optically active, keto-group stabilized amino-substituted sulfur ylides.
- Tolstikov, G. A.,Galin, F. Z.,Lakeev, S. N.,Khalilov, L. M.,Sultanova, V. S.
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p. 535 - 541
(2007/10/02)
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- N-Aryl-O-(α-aminoacyl)hydroxylamines: Model Reactions for the Activation of Monocyclic Aromatic Amines into Ultimate Carcinogens with α-Amino Acids
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The rearrangement of the new α-aminohydroxamic acids 15 and 18 to the likewise new N-(α-aminoacyloxy)arylamines 19 and 20, respectively, is observed in amine-catalyzed model reactions.N-(acyloxy)arylamines such as 19 and 20 are indicated to be ultimate carcinogens of aromatic amines which are able to react with bionucleophiles such as the DNA bases.The formation of 19 and 20 was proven by trapping these reactive intermediates with the model nucleophile N-methylaniline (21) to give the hydrazines 22 and - depending on the substituent in 19 and 20 - the so-called ortho amination products 23.Analogous reactions of the aceto- and pivalohydroxamic acids 24 and 25 lead also to the adducts 22 and 23, respectively, in comparable yields.These results demonstrate that the O-α-aminoacylation as shown here may be similarily used in model reactions for the activation of carcinogenic aromatic amines as the O-acetylation.
- Meier, Chris,Boche, Gernot
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p. 1691 - 1698
(2007/10/02)
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