cas 37088-66-7, METHYL (3S)-3-AMINO-3-PHENYLPROPANOATE

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New amino acid clubbed Schiff bases inhibit carbonic anhydrase II, α-glucosidase, and urease enzymes: in silico and in vitro
Combating pathological conditions related to hyperactivity of enzymes remains a formidable challenge for health. Small molecules therapy constitutes one of the means to circumvent the medical disorders resulting from enzyme hyperactivity. In this regard, we have synthesized structurally diverse amino acid hybrid Schiff bases (5a–5l and 10a–10k) and evaluated them for carbonic anhydrase II, α-glucosidase, and urease inhibitory potential. These new chemical scaffolds showed variable efficacies against the selected enzymes. The results indicated that compounds 5b (11.8 ± 1.33 μM), 10i (83.3 ± 1.13 μM), and 10f (88.2 ± 2.27 μM) are the most active scaffolds against carbonic anhydrase II, α-glucosidase, and urease, respectively. A structure–activity relationship revealed the most structural features contributing to the overall activities. Molecular docking suggested that these compounds possess excellent binding interactions with the active site residues of the targets by interacting through hydrogen bonding, π–π, and π–cation interactions.
Al-Harrasi, Ahmed,Al-Yahyaei, Balqees Essa Mohammad,Csuk, Rene,Halim, Sobia Ahsan,Khan, Ajmal,Khan, Majid,Khiat, Mohammed,Muhammed, Niaz,Rafiq, Kashif,Shah, Zarbad,Ur Rehman, Najeeb
p. 712 - 728
(2021/01/18)

NECROSIS INHIBITORS
The invention provides amides that inhibit cellular necrosis and/or human receptor interacting protein 1 kinase (RIP1), including corresponding sulfonamides, and pharmaceutically acceptable salts, hydrides and stereoisomers thereof. The compounds are employed in pharmaceutical compositions, and methods of making and use, including treating a person in need thereof with an effective amount of the compound or composition, and detecting a resultant improvement in the person's health or condition.
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Paragraph 0499; 0500; 0501

(2016/07/27)

Chiral Lewis Base-Catalyzed, Enantioselective Reduction of Unprotected β-Enamino Esters with Trichlorosilane
Catalytic asymmetric reduction of N-unsubstituted β-enamino esters represents a major challenge for asymmetric catalysis. In this paper, the first organocatalytic system that could be used for the asymmetric hydrosilylation of N-unsubstituted β-enamino esters has been developed. Using N-tert-butylsulfinyl-L-proline-derived amides and L-pipecolinic acid-derived formamides as catalyst, a broad range of β-aryl- and β-alkyl-substituted free β-amino esters could be prepared with high yields and enantioselectivities. The practicality was illustrated by the gram-scale asymmetric synthesis of ethyl (R)-3-amino-3-phenylpropanoate and isopropyl (S)-3-amino-4-(2,3,5-trifluorophenyl)butanoate. The resulting product can be smoothly transformed to the FDA approved medicines dapoxetine and sitagliptin in a short synthetic route.
Ye, Jianheng,Wang, Chao,Chen, Lin,Wu, Xinjun,Zhou, Li,Sun, Jian
p. 1042 - 1047
(2016/04/19)

Efficient synthesis of β'-amino-α, β-unsaturated ketones
A general and simple procedure to access chiral β'-amino-α, β-enones, in seven steps, from an α,β unsaturated ester has been described. The use of a Horner-Wadsworth-Emmons reaction as a key step for generating the β'-amino-α,β-enones, permits access to a range of substrates under mild conditions and in moderate to high yield.
Abrunhosa-Thomas, Isabelle,Plas, Aurelie,Kandepedu, Nishanth,Chalard, Pierre,Troin, Yves
p. 486 - 495
(2013/04/23)

Access to 2,6-disubstituted piperidines: Control of the diastereoselectivity, scope, and limitations. applications to the stereoselective synthesis of (-)-solenopsine A and alkaloid (+)-241D
Scope and limitations in the diastereoselective preparation of 2,6-cis or 2,6-trans disubstituted piperidines are described, through intramolecular reaction of chiral β′-carbamate-α,β-unsaturated ketone. This methodology has been applied to the total synthesis of a few well chosen examples, such as (-)-solenopsine A and alkaloid (+)-241D.
Abrunhosa-Thomas, Isabelle,Plas, Aurelie,Vogrig, Alexandre,Kandepedu, Nishanth,Chalard, Pierre,Troin, Yves
p. 2511 - 2526
(2013/04/24)

Carica papaya lipase catalysed resolution of β-amino esters for the highly enantioselective synthesis of (S)-dapoxetine
An efficient synthesis of the (S)-3-amino-3-phenylpropanoic acid enantiomer has been achieved by Carica papaya lipase (CPL) catalysed enantioselective alcoholysis of the corresponding racemic N-protected 2,2,2-trifluoroethyl esters in an organic solvent. A high enantioselectivity (E > 200) was achieved by two strategies that involved engineering of the substrates and optimization of the reaction conditions. Based on the resolution of a series of amino acids, it was found that the structure of the substrate has a profound effect on the CPL-catalysed resolution. The enantioselectivity and reaction rate were significantly enhanced by switching the conventional methyl ester to an activated trifluoroethyl ester. When considering steric effects, the substituted phenyl and amino groups should not both be large for the CPL-catalysed resolution. The mechanism of the CPL-catalysed enantioselective alcoholoysis of the amino acids is discussed to delineate the substrate requirements for CPL-catalysed resolution. Finally, the reaction was scaled up, and the products were separated and obtained in good yields (≥ 80 %). The (S)-3-amino-3- phenylpropanoic acid obtained was used as a key chiral intermediate in the synthesis of (S)-dapoxetine with very high enantiomeric excess (> 99 %). A carica papaya lipase catalysed resolution of N-protected β-phenylalanine esters has been developed. High enantioselectivity was achieved by two strategies that involved engineering of the substrates and optimization of the reaction conditions. After 50 % conversion, the products were separated and used as key chiral intermediates for the synthesis of (S)-dapoxetine with > 99 % ee. Copyright
You, Pengyong,Qiu, Jian,Su, Erzheng,Wei, Dongzhi
p. 557 - 565
(2013/03/13)

Stereoselective synthesis and in vivo evaluation of the analgesic activity of polysubstituted bispidines
Hetero-Michael addition on a chiral β'-amino α,β- unsaturated ketone gave, after some structural modifications, β,β'-diamino ketals. Mannich-type reactions of these diamines with an aldehyde led, with high diastereoselectivity, to trisubstituted piperidines. Another highly stereoselective Mannich cyclization, with an N-acyliminium ion generated in situ from the corresponding imide, allowed the preparation of original polycyclic bispidine derivatives. The antinociceptive effect of the three compounds prepared was evaluated in vivo by using the writhing test. If the biological results for the analgesic properties were disappointing, compared with the bispidine HZ2, which has a high affinity for opioid receptors, the modularity of the approach offered the possibility of introducing many substituents for new applications, which was promising because the bispidine core has been described to have many different activities. Total stereoselective synthesis of bispidine derivatives is achieved by using as two successive Mannich reactions key steps. This process constitutes a powerful approach toward the preparation of a polycyclic bispidine backbone with high enantioselectivity.
Plas, Aurelie,Troin, Yves,Chalard, Pierre,Marchand, Fabien,Eschalier, Alain
supporting information
p. 6070 - 6079,10
(2020/09/02)

AGONISTS THAT ENHANCE BINDING OF INTEGRIN-EXPRESSING CELLS TO INTEGRIN RECEPTORS
A method of enhancing binding of cells to an integrin-binding ligand comprises treating integrin-expressing cells in vitro with an agonist of integrin, wherein the integrin is selected from the group consisting of α4β1, α5β1, α4β7, αvβ3 and αLβ2, and contacting the treated cells with an integrin-binding ligand; integrin agonist compounds having the general formula I; methods of treating integrin-expressing cells with such agonists to enhance binding; and therapeutic methods comprising administering agonist-treated cells or agonist compounds to a mammal.
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(2012/06/01)

Practical, catalytic enantioselective hydrogenation to synthesize N -unprotected β-amino esters
Practical and simple catalytic enantioselective hydrogenation reactions to synthesize N-unprotected β-amino esters have been developed: (1) asymmetric hydrogenation of N-unprotected β-enamine ester and (2) asymmetric direct reductive amination of β-keto esters using ammonium salts. A Ru-DM-SEGPHOS complex was used as the catalyst in both cases and gave high enantioselectivity, high reactivity, and wide substrate applicability. These protocols greatly reduced reaction time and waste compared to conventional synthetic routes. The direct reductive amination route was demonstrated on a >100 kg scale.
Matsumura, Kazuhiko,Zhang, Xiaoyong,Hori, Kiyoto,Murayama, Toshiyuki,Ohmiya, Tadamasa,Shimizu, Hideo,Saito, Takao,Sayo, Noboru
experimental part
p. 1130 - 1137
(2012/01/03)

Stereoselective chemoenzymatic preparation of β-amino esters: Molecular modelling considerations in lipase-mediated processes and application to the synthesis of (S)-dapoxetine
A wide range of optically active 3-amino-3-arylpropanoic acid derivatives have been prepared by means of a stereoselective chemoenzymatic route. The key step is the kinetic resolution of the corresponding β-amino esters. Although the enzymatic acylations of the amino group with ethyl methoxyacetate showed synthetically useful enantioselectivities, the hydrolyses of the ester group catalyzed by lipase from Pseudomonas cepacia have been identified as the optimal processes concerning both activity and enantioselectivity. The enantiopreference of this lipase in these reactions has been explained, at the molecular level, by using a fragment-based approach in which the most favoured binding site for a phenyl ring and the most stable conformation of the 3-aminopropanoate core nicely match the (S)-configuration of the major products. The conversion and enantioselectivity values of the enzymatic reactions have been compared in order to understand the influence of the different substitution patterns present in the phenyl ring. This chemoenzymatic route has been successfully applied to the preparation of a valuable intermediate in the synthesis of (S)-dapoxetine, which has been chemically synthesised in excellent optical purity.
Rodriguez-Mata, Maria,Garcia-Urdiales, Eduardo,Gotor-Fernandez, Vicente,Gotor, Vicente
supporting information; experimental part
p. 395 - 406
(2010/06/15)

Highly enantioselective synthesis of β-amino acid derivatives by the lewis base catalyzed hydrosilylation of β-enamino esters
A study was conducted to demonstrate highly enantioselective synthesis of β-amino acid derivatives by the Lewis base catalyzed hydrosilylation of βenamino esters. It was found that these catalyst and its analogue displayed excellent activities and enantioselectivities in promoting hydrosilylation of N-aryl β-enamino esters. N-picolinoylpyrrolidine derivatives and N-picolioylephedrine were also evaluated in hydrosilylation of (Z)-methyl 3-phenyl-3-(phenylamino)acrylate. The generality of the Lewis base organocatalyzed hydrosilylation of various β-enamino esters were examined under the optimized conditions. It was observed that the catalytic system exhibited a high sensitivity to the N-substituents, while all the N-aryl β-enamino esters underwent the hydrosilylation smoothly to give corresponding β-amino esters.
Zheng, Hong-Jie,Chen, Wen-Bing,Wu, Zhi-Jun,Deng, Jin-Gen,Lin, Wen-Qing,Yuan, Wei-Cheng,Zhang, Xiao-Mei
supporting information; experimental part
p. 9864 - 9867
(2009/10/02)

PREPARATION AND UTILITY OF CCR5 INHIBITORS
Disclosed herein are substituted 8-azabicyclo[3.2.1]octane-based anti-infective agents of Formula I, processes of preparation thereof, pharmaceutical compositions thereof, and methods of use thereof.
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Page/Page column 39

(2008/12/06)

Structures of β-amino ester enolates: New strategies using the method of continuous variation
The solution structures of four enolates derived from β-amino esters are investigated using 6Li NMR spectroscopy in conjunction with the method of continuous variation (method of Job). Ensembles of homo- and heteroaggregated enolates are generated by mixing enantiomers ofa single enolate (R/S mixtures), opposite antipodes of two different en olates (R/S mixtures), and the same antipodes of two different enolates (RIR mixtures). The numbers of observable aggregates and their dependence on the mole fraction of the two enolates confirm the hexamer assignments. Inherent symmetries observable in the 6Li NMR spectra show the stereochemistry of chelation about the hexagonal drum.
Liou, Lara R.,McNeil, Anne J.,Toombes, Gilman E. S.,Collum, David B.
supporting information; experimental part
p. 17334 - 17341
(2009/09/07)

Development of a bulk enabling route to maraviroc (UK-427,857), a CCR-5 receptor antagonist
A bulk enabling synthesis of the CCR-5 receptor antagonist, Maraviroc (UK-427,857) (1), is presented. Synthesis of the three key fragments, β-amino ester 3,4,4-difluorohexanecarboxylic acid (2), and 1,3,4-triazole-substituted tropane fragment 4 are described. Coupling strategies for these fragments are discussed and described, including synthetic challenges, protection strategies, impurity generation, and final scale-up of the developed route to 1.
Haycock-Lewandowski, Sarah J.,Wilder, Alexander,Ahman, Jens
p. 1094 - 1103
(2013/01/03)

Discovery of a novel CCR5 antagonist lead compound through fragment assembly
CCR5, as the major co-receptor for HIV-1 entry, is an attractive novel target for the pharmaceutical industry in the HIV-1 therapeutic area. In this study, based on the structures of maraviroc and 1,4-bis(4-(7-chloroquinolin-4- yl)piperazin-1-yl)butane-1,4-dione (1), which was identified using structure-based virtual screening in conjunction with a calcium mobilization assay, a series of novel small molecule CCR5 antagonists have been designed and synthesized through fragment assembly. Preliminary SARs were obtained, which are in good agreement with the molecular binding model and should prove helpful for future antagonist design. The novel scaffold presented here might also be useful in the development of maraviroc-derived second generation CCR5 antagonists.
Liu, Yanqing,Zhou, Enkun,Yu, Kunqian,Zhu, Jin,Zhang, Yu,Xie, Xin,Li, Jian,Jiang, Hualiang
experimental part
p. 2426 - 2441
(2009/04/11)

3-AMINO-3-ARYLPROPIONIC ACID n-ALKYL ESTERS, PROCESS FOR PRODUCTION THEREOF, AND PROCESS FOR PRODUCTION OF OPTICALLY ACTIVE 3-AMINO-3-ARYLPROPIONIC ACIDS AND ESTERS OF THE ANTIPODES THERETO
The present invention is to provide an n-alkyl 3-amino-3-arylpropionate represented by the formula (I): wherein Ar1 represents an aryl group which may have a substituent(s), provided that a phenyl group and 4-methoxyphenyl group are excluded, R1 represents an n-propyl group or an n-butyl group, and a process for preparing the same, and its optically active compound and an optically active (S or R)-3-amino-3-arylpropionic acid represented by the formula (III-a): wherein Ar represents an aryl group which may have a substituent(s), and * represents an asymmetric carbon, and a process for preparing an optically active n-alkyl (R or S)-3-amino-3-arylpropionate represented by the formula (IV-a): wherein Ar and R1 have the same meanings as defined above, * represents an asymmetric carbon, provided that it has a reverse absolute configuration to the compound of the formula (III-a).
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Page/Page column 25-26

(2008/06/13)

PROCESS FOR PRODUCING AMINO ACID DERIVATIVES
The present invention relates to a process for producing amino acid derivatives such as optically active β-amino acid in short steps with good yield and high optical purity, which comprises reacting a keto acid of the formula (1): wherein R1 is hydrogen, an optionally substituted hydrocarbon, etc.; R2 is a spacer; and R3 is an optionally substituted alkoxy, etc., or a salt thereof, with ammonia or an amine or a salt thereof in the presence of a chiral catalyst and in the presence or absence of an acid and/or a fluorine-containing alcohol, to give an amino acid derivative of the formula (2): wherein Q is a group formed by removing one hydrogen atom from ammonia or an amine; X' is an acid and/or a fluorine-containing alcohol; and b is 0 or 1.
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Page/Page column 55-56

(2008/06/13)

PROCESS FOR THE PREPARATION OF ENANTIOMERICALLY ENRICHED BETA AMINO ACID DERIVATIVES
The present invention relates to a process for the efficient preparation of enantiomerically enriched beta amino acid derivatives wherein the amino group is unprotected. The product chiral beta amino acid derivatives are useful in the asymmetric synthesis of biologically active molecules. The process comprises an enantioselective hydrogenation of an amine-unprotected prochiral beta-amino acrylic acid or derivative thereof in the presence of a rhodium metal precursor complexed with a chiral mono- or bisphosphine ligand.
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Page/Page column 27-28

(2008/06/13)

ARYLAMIDES
The invention relates to compounds of formula (I), to a method for their production, to pharmaceutical compositions containing said compounds and to their use for the treatment and/or prophylaxis of human or animal diseases, in particular bacterial infections.
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Page/Page column 48-49

(2010/02/06)

SUBSTITUTED ALKYLAMIDES
The invention relates to compounds, method for producing them, pharmaceutical compositions comprising them and the use thereof in the treatment and/or prophylaxis of human or animal diseases, especially bacterial infectious diseases.
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Page/Page column 38

(2010/02/10)

Method for producing an optically active beta-amino acid
To provide a producing method of an optically active β-amino acid useful as intermediate for the production of medicines, agricultural chemicals and physiologically active substances, by means of a catalytic and asymmetric synthesis method of high performance and a high enantiomeric excess, without requiring additional procedures such as introduction and removal of protecting group and so on. A producing method of an optically active β-amino acids which comprises subjecting an enamine to an asymmetric hydrogenation.
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Page 13-14

(2010/02/06)

Highly efficient synthesis of β-amino acid derivatives via asymmetric hydrogenation of unprotected enamines
A direct asymmetric hydrogenation of unprotected enamino esters and amides is described. Catalyzed by Rh complexes with Josiphos-type chiral ligands, this method gives β-amino esters and amides in high yield and high ee (93-97% ee). No acyl protection/deprotection is required. Copyright
Hsiao, Yi,Rivera, Nelo R.,Rosner, Thorsten,Krska, Shane W.,Njolito, Eugenia,Wang, Fang,Sun, Yongkui,Armstrong III, Joseph D.,Grabowski, Edward J. J.,Tillyer, Richard D.,Spindler, Felix,Malan, Christophe
p. 9918 - 9919
(2007/10/03)

Tropane derivatives useful in therapy
The present invention provides compounds of the formula: wherein R1 is C3-6 cycloalkyl optionally substituted by one or more fluorine atoms, or C1-6 alkyl optionally substituted by one or more fluorine atoms, or C3-6 cycloalkylmethyl optionally ring-substituted by one or more fluorine atoms; and R2 is phenyl optionally substituted by one or more fluorine atoms, to pharmaceutically acceptable salts and solvates thereof, and to processes for the preparation of, intermediates used in the preparation of, compositions containing and the uses of, such compounds.
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(2008/06/13)

Enantioselective addition of ketene silyl acetals to nitrones catalyzed by chiral titanium complexes. Synthesis of optically active β-amino acids
A chiral titanium complex, Ti(O-i-Pr)4/BINOL/tert-butylcatechol, catalyzes enantioselective addition reaction of ketene silyl acetals to nitrones to give optically active β-amino acid derivatives which are biologically active compounds and useful synthetic intermediates of natural products and pharmaceuticals such as β-lactam antibiotics. The combined process of catalytic oxidation of secondary amines and enantioselective carbon-carbon bond formation of nitrones thus obtained with ketene silyl acetals provides a useful two-step method for the synthesis of optically active β-amino acid derivatives and related nitrogen compounds. Copyright
Murahashi, Shun-Ichi,Imada, Yasushi,Kawakami, Toru,Harada, Kazuhito,Yonemushi, Yoshiharu,Tomita, Naomi
p. 2888 - 2889
(2007/10/03)

Modulators of CCR5 chemokine receptor activity
Compounds of Formula I: (wherein R1, R2, R3, R4, Q, and X are defined herein) are described. The compounds are modulators of CCR5 chemokine receptor activity. The compounds are useful, for example, in the prevention or treatment of infection by HIV and the treatment of AIDS, as compounds or pharmaceutically acceptable salts, or as ingredients in pharmaceutical compositions, optionally in combination with other antivirals, immunomodulators, antibiotics or vaccines. Methods of treating AIDS and methods of preventing or treating infection by HIV are also described.
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(2008/06/13)

A convenient synthesis of chiral β3-amino acids
A novel method for the synthesis of chiral β3-amino acids is developed where the acid functionality was built by oxidative cleavage of an α-allylic group that was introduced by Evans' asymmetric alkylation of an appropriate acid substrate and the amino part came from the amide of the original carboxyl group following a modified Hofmann rearrangement reaction.
Chakraborty, Tushar K.,Ghosh, Animesh
p. 2039 - 2040
(2007/10/03)

Asymmetric Mannich-type reactions with a chiral acetate: Effect of Lewis acid on activation of aldimine
We introduce here a strategy that enables effective addition of lithium enolates of acetates to aldimines. The new method depends strongly on the use of ortho-alkoxy (or ortho-fluoro) aniline-derived aldimines which found to have a potential effect on the enolate addition. This scope was expanded to the asymmetric process using the chiral acetate, which has optically pure 2,6-bis(2-isopropylphenyl)-3,5-dimethylphenol as a chiral auxiliary with axial chirality. A Lewis acid additive is likely to have a complementary role in the pronounced activation of imine functionalities in the Mannich-type addition of the bulky chiral acetate.
Saito, Susumu,Hatanaka, Keiko,Yamamoto, Hisashi
p. 875 - 887
(2007/10/03)

An allyltitanium derived from acrolein 1,2-dicyclohexylethylene acetal and (η2-propene)Ti(o-i-Pr)2 as a chiral propionaldehyde homoenolate equivalent that reacts with imines with excellent stereoselectivity. An efficient and practical access to optically active γ-amino carbonyl compounds
A chiral allyltitanium compound 2, prepared in situ by the reaction of optically active acrolein 1,2-dicyclohexylethylene acetal (3) with (η2-propene)Ti(O-i-Pr)2 (1), reacts with a variety of acyclic and cyclic imines 4 in a regiospecific way to afford α-addition products 5 as a mixture of the E- and Z-isomers in good combined yield, where the former is predominant in a ratio of 92: 8 to >95:5. The mixture of (E)- and (Z)-5 and pure (E)-5 which could be isolated in several cases were respectively converted to the corresponding β-amino ester 6 to confirm the absolute configuration and enantiomeric purity. The ee of the newly formed asymmetric center of 5 is more than 78% for the mixture of (E)- and (Z)-5 and more than 96% for pure (E)-5. By taking advantage of the versatility of the vinyl ether moiety in 5, optically active γ-amino aldehydes 8, γ-amino aldehyde acetals 7 and 10, γ-amino acids 9, β-amino esters 6, and pyrrolidinoisoquinolines 12 were readily prepared. In the reaction of 2 with optically active α-silyloxyimine 4n, remarkable double stereodifferentiation was observed; thus, the reaction of 2 derived from (S,S)- or (R,R)-3 provided syn- and anti-5n in a ratio of 55:45 or 0:100, respectively. Meanwhile, the stereochemistry of the product in the reaction of 2 with β-silyloxyimine 4o was controlled mainly by 2. Thus, the reaction of β-silyloxyimine 14 with 2 derived from 1 and (R,R)-3 afforded γ-silyloxyimine 15 with 92% diastereoselectivity, from which 4-amino6-hydroxypentadecanal dimethyl acetal (13), a key intermediate for the synthesis of batzelladine D, was synthesized.
Okamoto,Teng,Fujii,Takayama,Sato
p. 3462 - 3471
(2007/10/03)

Asymmetric Mannich-type reactions of aldimines with a chiral acetate
(Formula presented) We introduce here a strategy that enables effective addition of lithium enolates of acetates to aldimines. The new method depends strongly on the use of o-alkoxy (or o-fluoro) aniline-derived aldimines which have been found to have a potential effect on the enolate addition. This scope was expanded to the asymmetric process using the chiral acetate. A Lewis acid additive has a complementary role in the pronounced activation of imine functionalities.
Saito, Susumu,Hatanaka, Keiko,Yamamoto, Hisashi
p. 1891 - 1894
(2007/10/03)

A chiral, oxidatively cleavable auxiliary in conjugate additions of lithium amides. Preparation of enantiomerically pure β-amino acid derivatives
Addition of enantiomerically, pure 4-methoxyphanethyl-substituted lithium amides to α,β-unsaturated esters leads to β-amino acid derivatives 4 - 7 with selectivities > 95: 5. The auxiliary can be cleaved by oxidation with cerium(IV) ammonium nitrate (CAN) and subsequent hydrolysis of the resulting mixture of imines.
Podlech, Joachim
p. 1779 - 1786
(2007/10/03)

Enantioselective acylation of β-aminoesters using penicillin G acylase in organic solvents
The resolution of racemic β-aminoesters has been achieved through selective acylation catalyzed by Penicillin G Acylase (ChiroCLEC(TM)-EC). The method has been optimized using three different phenylacetyl donors, and the effect of solvents on the rate of reaction is described. The efficiency of our method is illustrated by the synthesis of five different β-aminoesters with high enantiomeric purities.
Roche, Didier,Prasad, Kapa,Repic, Oljan
p. 3665 - 3668
(2007/10/03)

Metal-Templated Macrolactamization of Triamino and Tetramino Esters. Facile Synthesis of Macrocyclic Spermidine and Spermine Alkaloids, (S)-(+)-Dihydroperiphylline, (±)-Buchnerine, (±)-Verbacine, (±)-Verbaskine, and (±)-Verbascenine
The total synthesis of spermidine and spermine alkaloids. (S)-(+)-dihydroperiphylline (1), (±)-buchnerine (2), (±)-verbacine (3), (±)-verbaskine (4), and (±)-verbascenine (5), is described. The construction of macrocyclic lactams has been efficiently accomplished by the metal-templated cyclization of triamino esters and tetraamino esters. It was also found that the antimony(III) ethoxide is useful as an intermolecular amidation catalyst.
Kuroki, Yoshichika,Ishihara, Kazuaki,Hanaki, Naoyuki,Ohara, Suguru,Yamamoto, Hisashi
p. 1221 - 1230
(2007/10/03)

95. Asymmetric synthesis of the alkaloids mayfoline and N(1)-Acetyl-N(1)-deoxymayfoline
The total syntheses of the spermidine alkaloids (-)-mayfoline (11) and (+)-N(1)-acetyl-N(1)-deoxymayfoline (12) are described. These macrocyclic lactams belong to the most interesting conjugates of the polyamine derivatives very commonly found in nature. The enantioselective syntheses were achieved through resolution of the methyl 3-amino-3-phenylpropanoate (2) by recrystallization of its (+)-L-tartrate salt. Construction of the 13-membered ring ensued through condensation, reductive ring expansion (internal bond cleavage), and finally a transamidation reaction involving a second ring expansion.
Kuehne, Paul,Linden, Anthony,Hesse, Manfred
p. 1085 - 1094
(2007/10/03)

Enantioselective Synthesis of β-Amino Acids. 6. High 1,2-Stereoinduction in the Preparation of Enantiopure 2(R)-Hydroxy-3(R)-N-benzoylamino-3-phenylpropionic Acid (Like Stereoisomer of Taxol's Side Chain).
The remarkably high 1,2-stereoinduction encountered in the hydroxylation of 1-benzoyl-3-methyl-6(S)-phenylperhydropyrimidin-4-one allows for the preparation of enantiopure N-benzoyl (2R,3R)-3-phenylisoserine, the like stereoisomer of taxol's C-13 side chain.
Escalante, Jaime,Juaristi, Eusebio
p. 4397 - 4400
(2007/10/02)

Asymmetric Syntheses of β-Phenylalanine, α-Methyl-β-phenylalanines and Derivatives
A strategy of highly stereoselective conjugate additions of lithium (R)-(α-methylbenzyl)benzylamide to tert-butyl cinnamate and its 2-methyl derivative combined with appropriate tandem or sequential electrophilic quenches allows the asymmetric syntheses of β-phenylalanyl (95percent enantiomeric excess) and homochiral (2R,3S)- and (2S,3S)-α-methyl-β-phenylalanine and the corresponding β-lactams (3R,4S)- and (3S,4S)-3-methyl-4-phenylazetidinones.
Davies, Stephen G.,Garrido, Narciso M.,Ichihara, Osamu,Walters, Iain A. S.
p. 1153 - 1155
(2007/10/02)

Asymmetric Synthesis of Sulfinimines: Applications to the Synthesis of Nonracemic β-Amino Acids and α-Hydroxy-β-amino Acids
Asymmetric oxidation of sulfenimines 1 affords sulfinimines 2 (88-90percent ee) which are chiral ammonia imine synthons useful in the enantioselective synthesis of β-amino acids and α-hydroxy-β-amino acids such as the C-13 side chain of taxol (2R,3S)-7.
Davis, Franklin A.,Reddy, R. Thimma,Reddy, Rajarathnam E.
p. 6387 - 6389
(2007/10/02)

A convenient diastereoselective total synthesis of andrimid
A convenient diastereoselective synthesis of andrimid was accomplished in a straightforward approach and also several β-substituted cyclic imides were prepared in a facile manner.
Rama Rao,Singh,Varaprasad
p. 4393 - 4396
(2007/10/02)

THE USE OF β-LACTAMS IN THE SYNTHESIS OF SPERMINE AND SPERMIDINE ALKALOIDS. TOTAL SYNTHESIS OF HOMALINE
The optically active plant product homaline (6) has been synthesized in a convergent sequence starting with β-phenyl-β-alanine and putrescine (14).The key transformation in this sequence is the ring expansion by transamidation of a functionalized chiral β-lactam precursor.
Wasserman, Harry H.,Berger, Gregory D.
p. 2459 - 2464
(2007/10/02)