- Synthesis of pyrrolizidines via Copper(I) catalyzed radical atom transfer cyclization
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Trachelanthamidine and pseudoheliotridane are synthesized from (2S)-N-trichloroacetyl-2-vinylpyrrolidine (5) by a 5-exo-trig radical cyclization. The intermediate radical is generated heating 5 in a sealed tube (CH3CN/160°C) using CuCl as catal
- Seijas,Vazquez-Tato,Castedo,Estevez,Onega,Ruiz
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Read Online
- Chemoenzymatic synthesis and inhibitory activities of hyacinthacines A 1 and A2 stereoisomers
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A novel straightforward chemoenzymatic procedure for the synthesis of hyacinthacine stereoisomers based on the aldol addition of dihydroxyacetone phosphate (DHAP) to N-Cbz-prolinal under catalysis by L-rhamnulose 1-phosphate aldolase from E. coli is prese
- Calveras, Jordi,Casas, Josefina,Parella, Teodor,Joglar, Jesus,Clapes, Pere
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Read Online
- Synthesis and absolute configuration of 2-(12'-aminotridecyl)-pyrrolidine, a defensive alkaloid from the Mexican bean beetle, Epilachna varivestis
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The synthesis of 2-(12'-aminotridecyl)-pyrrolidine (1), a defensive alkaloid recently isolated from the Mexican bean beetle, Epilachna varivestis, is described. The (2S,12'R) configuration is assigned to this alkaloid by comparing the 1H NMR spectrum of its (S)-MTPA derivative with that of (R)- and (S)-MTPA [α-methoxy-α-(trifluoromethyl)phenylacetyl] derivatives of the synthetic sample. These results suggest that the seventeen carbon skeleton of 1 is acetate rather than proline derived.
- Shi,Attygalle,Xu,Ahmad,Meinwald
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Read Online
- Discovery of substituted 3H-pyrido[2,3-d]pyrimidin-4-ones as potent, biased, and orally bioavailable sst2 agonist
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The discovery of a novel 3H-pyrido[2,3-d]pyrimidin-4-one series as potent and biased sst2 agonists is described. This class of molecules exhibits excellent sst2 potency and selectivity against sst1, sst3, and sst5 receptors, and they are significantly more potent at inhibiting cAMP production than inducing internalization. The orally bioavailable 6-(3-chloro-5-methylphenyl)-3-(3-fluoro-5-hydroxyphenyl)-5-({methyl[(2S)-pyrrolidin-2-ylmethyl]amino}methyl)-3H,4H-pyrido[2,3-d]pyrimidin-4-one (36) also suppresses GH secretion in GHRH-challenged rats in a dose-dependent manner.
- Betz, Stephen F.,Chen, Zhiyong,Kusnetzow, Ana Karin,Nguyen, Julie,Rico-Bautista, Elizabeth,Struthers, R. Scott,Tan, Hannah,Zhao, Jian,Zhu, Yunfei
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supporting information
(2020/08/26)
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- Efficient synthesis of methyl (S)-4-(1-methylpyrrolidin-2-YL)-3-oxobutanoate as the key intermediate for tropane alkaloid biosynthesis with optically acitve form
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Methyl (S)-4-(1-methylpyrrolidin-2-yl)-3-oxobutanoate has been synthesized for enzymatic studies on cyclization enzymes during cocaine biosynthesis in Erythroxylum coca plants. During the present new synthesis, L-proline was first protected with Cbz group and reduced to chiral amino alcohol, which were then followed by Swern oxidation, Wittig reaction and decarboxylative condensation. At the last step, N-methylamino acid precursor was treated with 1,1'-carbonyldiimidazole followed by reacting with methyl potassium malonate to give the 3-oxobutanoate in 54% overall yield. This new strategy has proven to avoid obvious racemization of the L-proline chiral center during the synthesis. In addition, six of the eight synthesis steps were performed via GAP chemistry/technology without the use of column chromatography for purification.
- Katakam, Nanda Kumar,Seifert, Cole W.,D'Auria, John,Li, Guigen
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p. 604 - 613
(2019/08/01)
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- Synthesis of Nα-Z protected amino alkyl triazole acids and their application to neo-glycopeptides synthesis
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The synthesis of triazole linked glycopeptides employing 2-chloro-4,6-dimethoxy-1,3,5-triazine (CDMT) mediated coupling of Z-protected triazole acids with glycosyl amines and amino acid esters is described. The coupling proceeded smoothly at room temperat
- Madhu, Chilakapati,Panguluri, Nageswara Rao,Sureshbabu, Vommina V.
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p. 858 - 864
(2014/08/05)
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- Syntheses of chiral ferrocenophanes and their application to asymmetric catalysis
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N-Substituted 2-aza-[3]-ferrocenophanes were easily synthesized from 1,1′-ferrocenedicarbaldehyde and aliphatic amines in high yields. One of the ferrocenophanes served as a ligand for the copper-catalyzed oxidative coupling of 2-naphthol derivatives to give the products in good yields with up to 92% ee, and it also efficiently catalyzed the asymmetric Michael addition reaction as an organocatalyst.
- Zhang, Qiying,Cui, Xiuling,Chen, Lianmei,Liu, Haitao,Wu, Yangjie
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p. 7823 - 7829
(2015/01/16)
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- Synthesis of (R)-norbgugaine and its potential as quorum sensing inhibitor against Pseudomonas aeruginosa
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(R)-Bgugaine is a natural pyrrolidine alkaloid from Arisarum vulgare, which shows antifungal and antibacterial activity. In this Letter, we have accomplished the simple synthesis of norbgugaine (demethylated form of natural bgugaine) employing Wittig olefination and cat. hydrogenation as the key steps and its biological studies are reported for the first time. The synthesized norbgugaine was evaluated for inhibition of quorum sensing mediated virulence factors (motility, biofilm formation, pyocyanin pigmentation, rhamnolipid production and LasA protease) in Pseudomonas aeruginosa wherein swarming motility is reduced by 95%, and biofilm formation by 83%.
- Majik, Mahesh S.,Naik, Deepak,Bhat, Chinmay,Tilve, Santosh,Tilvi, Supriya,D'Souza, Lisette
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p. 2353 - 2356
(2013/05/09)
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- Henry-Nef reaction: A practical and versatile chiral pool route to 2-substituted pyrrolidine and piperidine alkaloids
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The paper describes the synergistic protocol developed by combinatorial Henry and Nef reaction for the synthesis of 2-substituted pyrrolidine and piperidine alkaloids containing 1,3-aminoketone and 1,3-amino alcohol units. The utility of the protocol is demonstrated by asymmetric synthesis of 12 natural products of which asymmetric synthesis of (-)-N-methylpelletierine is presented for the first time. The one-carbon homologation described also provides an alternate route for the synthesis of key intermediates homoprolinol and homopipecolinol used as synthetic precursors for several alkaloids and construction of β-amino acids from α-amino acids.
- Bhat, Chinmay,Tilve, Santosh G.
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p. 6129 - 6143
(2013/07/27)
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- Interfacial cavity filling to optimize CD4-mimetic miniprotein interactions with HIV-1 surface glycoprotein
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Ligand affinities can be optimized by interfacial cavity filling. A hollow (Phe43 cavity) between HIV-1 surface glycoprotein (gp120) and cluster of differentiation 4 (CD4) receptor extends beyond residue phenylalanine 43 of CD4 and cannot be fully accessed by natural amino acids. To increase HIV-1 gp120 affinity for a family of CD4-mimetic miniproteins (miniCD4s), we targeted the gp120 Phe43 cavity with 11 non-natural phenylalanine derivatives, introduced into a miniCD4 named M48 (1). The best derivative, named M48U12 (13), bound HIV-1 YU2 gp120 with 8 pM affinity and showed potent HIV-1 neutralization. It contained a methylcyclohexyl derivative of 4-aminophenylalanine, and its cocrystal structure with gp120 revealed the cyclohexane ring buried within the gp120 hydrophobic core but able to assume multiple orientations in the binding pocket, and the aniline nitrogen potentially providing a focus for further improvement. Altogether, the results provide a framework for filling the interfacial Phe43 cavity to enhance miniCD4 affinity.
- Morellato-Castillo, Laurence,Acharya, Priyamvada,Combes, Olivier,Michiels, Johan,Descours, Anne,Ramos, Oscar H. P.,Yang, Yongping,Vanham, Guido,Ari?n, Kevin K.,Kwong, Peter D.,Martin, Lo?c,Kessler, Pascal
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p. 5033 - 5047
(2013/07/26)
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- Stereoselective synthesis of chiral pyrrolidine derivatives of (+)-α-pinene containing a β-amino acid moiety
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We report the synthesis of several enantiopure pyrrolidine derivatives containing a β-amino acid moiety. These novel chiral compounds were prepared through stereospecific chlorosulfonyl isocyanate (CSI) addition to the readily available, natural terpene (+)-α-pinene. Coupling of N-Boc-protected β-amino acid derivatives with various bulky amines and amino acids using the mixed anhydride activation method, followed by N-deprotection, afforded the corresponding chiral amino amides in good yields. Despite the severe steric hindrance anticipated in α-pinene-based heterocycles, efficient coupling of the amino amides and an amino ester with the acyl chloride of N-Cbz-protected (S)-proline provided the corresponding pyrrolidinic pinene derivatives in good yields. Moreover, a convenient synthesis of N-Cbz- and N-Boc-monoprotected (S)-prolinamine is reported. Georg Thieme Verlag Stuttgart New York.
- Vega-Penaloza, Alberto,Sanchez-Antonio, Omar,Escudero-Casao, Margarita,Tasnadi, Gabor,Fueloep, Ferenc,Juaristi, Eusebio
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p. 2458 - 2468
(2013/09/23)
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- Hybrids of privileged structures benzothiazoles and pyrrolo[2,1-c] [1,4]benzodiazepin-5-one, and diversity-oriented synthesis of benzothiazoles
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Privileged structures like Benzothiazole and Pyrrolobenzodiazepine offer wonderful opportunity to explore in anti-cancer drug discovery as a mean to counter drug-resistance problem. BT-PBD hybrids and diverse BT derivatives have been synthesized and their in vitro cytotoxic activities were screened against five cancer cell lines have been discussed. The novel compounds showed promising results as compared with the marketed drug etoposide and could well be used in future anti-cancer drug development studies.
- Subhas Bose,Idrees, Mohd.,Todewale, Ismail K.,Jakka,Venkateswara Rao
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- An efficient and facile synthesis of N-Cbz-β-aminoalkanesulfonamides
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An efficient method for the synthesis of N-Cbz-β- aminoalkanesulfonamides was described. N-Cbz-β-aminoalkanesulfona-mides were readily prepared in good yields from a variety of amino alcohols, including optically active ones, via N-Cbz protection with ben
- Meng, Fanhua,Chen, Ning,Xu, Jiaxi
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p. 2548 - 2553
(2013/06/27)
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- Asymmetric Michael additions catalysed by functionalised quaternary alkylammonium ionic liquids
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Some functionalised quaternary alkylammonium ionic liquids were synthesised and examined as organocatalysts for asymmetric Michael additions of aldehydes and ketones to nitroolefins. All of them exhibited excellent enantioselectivities (>99% ee) and diast
- Wang, Ge,Sun, Huichao,Cao, Xiaohui,Li, Yang,Chen, Ligong
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scheme or table
p. 96 - 99
(2012/05/07)
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- Chiral pyrrolidine quaternary derivatives as organocatalysts for asymmetric Michael additions
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A series of chiral pyrrolidine quaternary derivatives were designed and synthesized. It was found that these derivatives are highly efficient organocatalysts for the asymmetric Michael addition reactions of aldehydes and ketones to nitroolefins with high
- Sun, Huichao,Wang, Ge,Yan, Xilong,Chen, Ligong
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p. 1501 - 1509
(2012/10/29)
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- Synthesis of (-)-hygrine, (-)-norhygrine, (-)-pseudohygroline and (-)-hygroline via Nef reaction
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Synthesis of tropane alkaloids (-)-hygrine, (-)-norhygrine and sedum alkaloids (-)-pseudohygroline and (-)-hygroline is described from l-proline via Henry and Nef reactions.
- Bhat, Chinmay,Tilve, Santosh G.
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p. 6566 - 6568
(2012/01/02)
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- Conformationally stabilized catalysts by fluorine insertion: Tool for enantioselectivity improvement
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F rigid cats: The power of conformationally stabilized catalysts is demonstrated. By taking appropriate advantage of fluorine insertion (see scheme), purely conformational catalyst design led to a notable improvement in enantioselectivities from around 70% to 91-98.5% ee. The other advantage of this approach is the better understanding of the origin of the stereoselectivity in the given catalytic system. Copyright
- Quintard, Adrien,Langlois, Jean-Baptiste,Emery, Daniel,Mareda, Jiri,Guenee, Laure,Alexakis, Alexandre
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supporting information; experimental part
p. 13433 - 13437
(2012/01/05)
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- Synthesis of chiral NADH analog based on proline template including thiourea and nicotinic acid moieties
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Chiral reductase-mimicking organic molecule built on proline template incorporating a covalently bound NADH mimic via thiourea, and related reducing agent Hantzsch dihydropyridine, was designed. A synthetic path was developed involving interlinking of chiral proline derivatives with thiourea and subsequent coupling reaction with nicotinoyl chloride. The structure of target compound was studied by x-ray, indicating a double H bond with thiourea hydrogens and oxygen O1 of benzylcarbamate fragment. The reduction of benzil and imines was performed. Taylor & Francis Group, LLC.
- Bagdziunas, Gintautas,Haukka, Matti,Butkus, Eugenijus
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scheme or table
p. 2517 - 2523
(2011/08/07)
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- Pyrrolidine-based chiral quaternary alkylammonium ionic liquids as organocatalysts for asymmetric Michael additions
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A series of chiral pyrrolidine-type quaternary alkylammonium ionic liquids were synthesized and served as efficient catalysts for asymmetric Michael additions of aldehydes and ketones to nitroolefins, and the corresponding adducts were obtained in excelle
- Wang, Ge,Sun, Huichao,Cao, Xiaohui,Chen, Ligong
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experimental part
p. 1324 - 1331
(2012/01/19)
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- Simple methodology for the preparation of amino alcohols from amino acid esters using nabh4-methanol in THF
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Amino alcohols constitute a very useful and versatile class of organic compounds, with important applications in synthetic and medicinal chemistry. However, in most of the procedures described in the literature for the obtainment of these compounds, considerable limitations can be found, such as drastic conditions, long time reactions, poor yields, and purification problems. The present article describes a methodology that gives amino alcohols and N-protected amino alcohols based on the reduction of amino acid esters under mild conditions, employing NaBH4 in the presence of methanol. The reactions occurred in a short time (15-20min) and provide yields of 50-95%.
- Goncalves,Pinheiro,Da Silva,Da Costa,Kaiser,De Souza
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experimental part
p. 1276 - 1281
(2011/05/04)
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- Aminal-pyrrolidine organocatalysts - Highly efficient and modular catalysts for α-functionalization of carbonyl compounds
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The substitution of the 4-position of hydroxyproline by a phenol group, together with an aminal on the 2-position, gave a synergistic effect leading to two powerful complementary organocatalysts. They show excellent enantiocontrol in the α-functionalization of a wide range of linear/ branched aldehydes and ketones, including Michael additions to ethenediyl disulfones or nitrostyrene and α-amination. We obtained ees up to 98.5 % with low catalyst loadings (down to 1 mol-%). As a proof of efficiency, TOFs of up to 1000 h-1 could be obtained.
- Quintard, Adrien,Belot, Sebastien,Marchai, Estelle,Alexakis, Alexandre
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supporting information; experimental part
p. 927 - 936
(2010/04/25)
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- Asymmetric organocatalysis of the addition of acetone to 2-nitrostyrene using N-diphenylphosphinyl-1,2-diphenylethane-1,2-diamine (PODPEN)
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The highly enantioselective addition of acetone to 2-nitrostyrene, using N-diphenylphosphinyl-trans-1,2-diphenylethane-1,2-diamine (PODPEN) as a catalyst, is described.
- Morris, David J.,Partridge, A. Simon,Manville, Charles V.,Racys, Daugidas T.,Woodward, Gary,Docherty, Gordon,Wills, Martin
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supporting information; experimental part
p. 209 - 212
(2010/03/24)
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- Organocerium additions to proline-derived hydrazones: Synthesis of enantiomerically enriched amines
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The addition of organocerium reagents (from both organolithium and organomagnesium precursors) to chiral aldehyde hydrazones prepared from 1-aminoproline derivatives has been studied. The additions proceed in good yield and high diastereoselectivity and with good nucleophile (Me, n-Bu, i-Pr, t-Bu, Ph, etc.) and substrate scope (alkyl, alkenyl and aryl). The resulting hydrazines can be converted to amines by N-N bond cleavage through hydrogenolysis (Raney nickel) or by acylation and cleavage with Li/NH 3. The influence of the side chain on the diastereoselectivity was investigated through variation of the substituents to include more coordinating atoms (oxygen and nitrogen) as well as the removal of coordinating atoms. The SAMEMP auxiliary bearing a 2-methoxyethoxymethyl group gave the highest diastereoselectivities. Remarkably, auxiliaries bearing simple methyl and isobutyl substituents gave high selectivities as well. Hypotheses for the origin of the selectivity are presented.
- Denmark, Scott E.,Edwards, James P.,Weber, Theodor,Piotrowski, David W.
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experimental part
p. 1278 - 1302
(2010/11/02)
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- Novel cyclic β-aminophosphonate derivatives as efficient organocatalysts for the asymmetric Michael addition reactions of ketones to nitrostyrenes
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Three novel catalysts based upon cyclic β-aminophosphonate derivatives 13 were designed to catalyze the asymmetric Michael addition reactions of ketones to β-nitrostyrenes. Among the catalysts that have been prepared in this study, cyclic β-aminophosphonic acid monoethylester 3 showed the highest catalytic ability, giving the corresponding Michael adduct in good yields, high enantioselectivities (up to 92%ee), and high diastereoselectivities (syn:anti up to 95:5).
- Widianti, Triana,Hiraga, Yoshikazu,Kojima, Satoshi,Abe, Manabu
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experimental part
p. 1861 - 1868
(2010/11/18)
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- Organocatalytic addition on l,2-bis(sulfone)vinylenes leading to an unprecedented rearrangement
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A study was conducted to demonstrate the use of 1,2-bis(sulfone)vinylenes in enamine catalysis. It was revealed that these sulfones led to a new rearrangement arising from a sulfone shift to the adjacent carbon atom. Investigations also revealed that the use of cheaper (Z)-1,2-bis(sulfone) vinylene lead to full conversion after a short reaction time in dioxane, using H2O as co-catalyst to accelerate the reaction. A careful NMR investigation indicated that the new product was gem-disulfone, which was supported by authentic sample.
- Quintard, Adrien,Alexakis, Alexandre
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supporting information; experimental part
p. 11109 - 11113
(2010/04/29)
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- Diversity-oriented synthesis towards conceptually new highly modular aminal-pyrrolidine organocatalysts
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A study was conducted to demonstrate the synthesis of animal-pyrrolidine derivatives and their applications in various Michael addition reactions. The animal-pyrrolidine organocatalysts were prepared from protected L-prolinal, which was obtained from commercially available Cbz-L-proline. Animal formations with various reoisomers were prepared, while catalysts were synthesized, to study the influence of the different substituents. It was observed that all catalysts were stable after prolonged conservation period. The newly synthesized catalysts were also tested in the reaction of proopinaldehyde with nitrostyrene. It was also observed that all the catalysts lead to full conversion after a short reaction time. The enantioselectivity varied from 49% in diastereoisomeric catalyst, to the best enantioselectivity of 79%, using reoisomer catalysts.
- Quintard, Adrien,Bournaud, Chloee,Alexakis, Alexandre
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supporting information; experimental part
p. 7504 - 7507
(2009/08/14)
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- First synthesis of Trans- and Cis-dendrochrysanines
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Trans- and cis-dendrochrysanines (1 and 2), isolated from t he stems of Dendrobium chrysanthum Wall., were first synthesized from l-proline. The absolute configuration of 1 and 2 was established to be S by the syntheses.{A figure is presented}. Dendrochry
- Konno, Hiroyuki,Kusumoto, Sayako,Kanai, Sotaro,Yamahana, Yasuyuki,Nosaka, Kazuto,Akaji, Kenichi
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p. 2579 - 2585
(2008/02/04)
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- TRICYCLIC COMPOUND, PROCESS FOR PRODUCING THE SAME, AND USE
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A compound of the formula: wherein R1 is a 5- or 6-membered ring; ???Z1 is a 5- or 6-membered aromatic ring; ???Z2 is a group of -Z2a-W2-Z2b-, wherein Z2a and Z2b are each O, S(O)q (wherein q is 0, 1 or 2), an imino group, or a bond; and W2 is an alkylene chain; ???W is a group represented by wherein R3 and R3' are each a hydrogen atom, a lower alkyl group, or a lower alkoxy group; X is CH or N; n and n' are each an integer of 0 or 1 to 4; m and m' are each 1 or 2; Y is O, S(O)p (wherein p is 0, 1 or 2), CH2 or NR4 (wherein R4 is a hydrogen atom, a lower alkyl group, or a lower acyl group); and ???R2 is (1) an amino group, in which the nitrogen atom may be converted to a quaternary ammonium or an oxide, or (2) a nitrogen-containing heterocyclic group which may contain a sulfur atom or an oxygen atom as the ring-constituting atom, in which the nitrogen atommay be converted to a quaternary ammonium or an oxide; or a salt thereof. The compound exhibits excellent CCR antagonist activity against CCR5, and is useful as a prophylactic and/or therapeutic agent for HIV infection in human peripheral blood mononuclear cells, especially for AIDS.
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Page/Page column 56-57
(2010/02/14)
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- A homo-proline tetrazole as an improved organocatalyst for the asymmetric Michael addition of carbonyl compounds to nitro-olefins
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A new homo-proline tetrazole derivative 7 has been prepared and shown to have improved properties for achieving asymmetric Michael addition of carbonyl compounds to nitro-olefins.
- Mitchell, Claire E. T.,Cobb, Alexander J. A.,Ley, Steven V.
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p. 611 - 614
(2007/10/03)
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- Determination of absolute configuration of Pandanus alkaloid, pandamarilactonine-A, by first asymmetric total synthesis
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The absolute configuration of pandamarilactonine-A, a pyrrolidine alkaloid, was established on the basis of total synthesis starting from l-prolinol. An insight into the mechanism of the low enantiomeric purity of natural pandamarilactonine-A is discussed
- Takayama, Hiromitsu,Sudo, Rie,Kitajima, Mariko
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p. 5795 - 5797
(2007/10/03)
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- NOVEL ANTIDIABETIC COMPOUNDS HAVING HYPOLIPIDAEMIC, ANTIHYPERTENSIVE PROPERTIES, PROCESS FOR THEIR PREPARATION AND PHARMACEUTICAL COMPOSITIONS CONTAINING THEM
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New thiazolidin-2,4-dione derivatives of formula (1) in which A, W, Q, B, D, X, Y, Z, R', k and p are defined as in claim 1; their tautomeric forms, their derivatives, their steroisomers, their polymorphs, their pharmaceutical acceptable salts, their pharmaceutically acceptable solvates and pharmaceutically acceptable compositions containing them. Methods for their preparation and their use as antidiabetic compounds are claimed.
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- Cyclic compounds
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1. A cyclic compound of the formula (I) or a pharmacologically acceptable salt thereof, wherein X is ═CH— or ═N—, Y is —NH—, —NR4—, —S—, —O—, —CH═N—, —N═CH—, —N═N—, —CH═CH—, etc., R1 is a lower alkoxy group, an amino group, a heterocyclic ring containing N atom(s), or a hydroxy group substituted by a heterocyclic ring containing N atom(s) (each of which is optionally substituted), R2 is a lower alkylamino group which is optionally substituted by an aryl group, a lower alkoxy group which is optionally substituted by an aryl group, a lower alkoxy group substituted by an aromatic heterocyclic ring containing N atom(s), R3 is an aryl group, a heterocyclic ring containing N atom(s), a lower alkyl group, a lower alkoxy group, a cyclo lower alkoxy group, a hydroxy group substituted by a heterocyclic ring containing N atom(s), or an amino group (each of which is optionally substituted), and R3 and a substituent in Y may be combined to form a lactone ring. The compound of the present invention has excellent selective PDE V inhibitory activity and therefore, is useful as a therapeutic or prophylactic drug for treating various diseases due to functional disorders on cGMP-signaling.
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- New Odorless Protocols for the Synthesis of Aldehydes and Ketones from Thiol Esters
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Dodecanethiol esters derived from odorless dodecanethiol proved to be suitable substrates for Pd-catalyzed reduction with triethylsilane, coupling with organozinc reagents, and coupling with terminal acetylenes.
- Miyazaki, Tohru,Han-Ya, Yuki,Tokuyama, Hidetoshi,Fukuyama, Tohru
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p. 477 - 480
(2007/10/03)
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- Synthesis and cholinergic affinity of diastereomeric and enantiomeric isomers of 1-methyl-2-(2-methyl-1,3-dioxolan-4-yl)- pyrrolidine, 1-methyl-2-(2-methyl-1,3-oxathiolan-5-yl)pyrrolidine and of Their iodomethylates
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Four out of the eight possible stereoisomers of 1-methyl-2-(2-methyl-1,3-dioxolan-4-yl)pyrrolidine, 1-methyl-2-(2-methyl-1,3-oxathiolan-5-yl)pyrrolidine and the corresponding iodomethylates have been synthesised. They were formally derived from hybridisat
- Dei, Silvia,Bellucci, Cristina,Buccioni, Michela,Ferraroni, Marta,Gualtieri, Fulvio,Guandalini, Luca,Manetti, Dina,Matucci, Rosanna,Romanelli, Maria Novella,Scapecchi, Serena,Teodori, Elisabetta
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p. 3153 - 3164
(2007/10/03)
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- An extremely simple, convenient and mild one-pot reduction of carboxylic acids to alcohols using 3,4,5-trifluorophenylboronic acid and sodium borohydride
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Acyloxyboron intermediates formed in situ from carboxylic acids and 3,4,5-trifluorophenylboronic acids react with sodium borohydride in THF to give alcohols in good to high yields.
- Tale,Patil,Dapurkar
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p. 3427 - 3428
(2007/10/03)
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- Organoruthenium(II) and (III) amidinates, (η5-C5Me5)Ru(η-amidinate) and (η5-C5Me5)RuCl(η-amidinate), as unique redox catalysts for the intramolecular Kharasch reactions: Facile access to a pyrrolizidine alkaloid skeleton under mild c
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A novel organoruthenium amidinate, (η5-C5Me5)RuCl(η-(i-Pr)N=C(Me)N(i-Pr)) (2), has been prepared by oxidation of organoruthenium amidinate, (η5-C5Me5)Ru(η-(iPr)N=C-Me)N(i-Pr)) (1), by organic chlorides; both 1 and 2 are found to be g
- Ngashima, Hideo,Gondo, Mitsuru,Masuda, Satoshi,Kondo, Hideo,Yamaguchi, Yoshitaka,Matsubara, Kouki
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p. 442 - 444
(2007/10/03)
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- Pyrrolidinic and piperidinic ring fission by conjugate elimination
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Treating N-substituted pyrrolidines and piperidines bearing an allylic chain α to the nitrogen with strong bases leads to the opening of the heterocycle and provides 1,3-dienes disubstituted with an alkoxy and an aminoalkyl chain. The effects of the base and the solvent have been studied, as well as the influence of the ring size and the nitrogen substituent. The results obtained suggest a possible pre-chelation of the base cation before the deprotonation.
- Acquadro, Francesco,Oulyadi, Hassan,Venturello, Paolo,Maddaluno, Jacques
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p. 8759 - 8763
(2007/10/03)
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- Synthesis and biological evaluation of an N10-Psec substituted pyrrolo[2,1-c][1,4]benzodiazepine prodrug
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The first example of an N10-protected (e.g., Psec, 15) pyrrolo[2,1-c][1,4]benzodiazepine (PBD) analogue that retains significant cytotoxicity in a number of tumour cell lines is reported. This prototype could lead to a new generation of clinically useful N10-protected PBD prodrugs.
- Berry, Jane M.,Howard, Philip W.,Kelland, Lloyd R.,Thurston, David E.
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p. 1413 - 1416
(2007/10/03)
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- Mild reduction of carboxylic acids to alcohols using cyanuric chloride and sodium borohydride
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Several carboxylic acids, including N-Boc, N-Cbz and N-Fmoc amino acids were reduced to the corresponding alcohols by activation of the carboxy function with cyanuric chloride and N-methylmorpholine followed by reduction with aqueous sodium borohydride.
- Falorni, Massimo,Porcheddu, Andrea,Taddei, Maurizio
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p. 4395 - 4396
(2007/10/03)
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- Antidiabetic compounds having hypolipidaemic, antihypertensive properties, process for their preparation and pharmaceutical compositions containing them
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Novel antidiabetic compounds, their tautomeric forms, their derivatives, their steroisomers, their polymorphs, their pharmaceutically acceptable salts, their pharmaceutically acceptable solvates and pharmaceutical acceptable compositions containing them: Methods for preparing the antidiabetic compounds and their uses.
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- The Synthesis of 5,6,7,7a-Tetrahydro-1-methyl-3H-pyrrolizin-3-one by the Palladium-Catalyzed Cyclization of N-Bromoacetyl-2-vinylpyrrolidine
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N-Bromoacetyl-2-vinylpyrrolidine underwent cyclization to give a pyrrolizidine derivative in the presence of a base and a catalytic amount of palladium catalyst.
- Yang, Shyh-Chyun,Shea, Fang-Rong,Hung, Chung-Wei
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p. 779 - 782
(2007/10/03)
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- Unexpected diastereoselectivity in AD of an L-proline-derived 1,1- disubstituted alkene
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Asymmetric dihydroxylation of the L-proline-derived 1,1-disubstituted alkene 5 catalysed by either (DHQ)2PHAL or (DHQD)2PHAL unexpectedly leads to preference for the same diastereomer 7, both reactions proceeding with apparently matching double diastereoselectivity. In contrast, AD using the analogous (DHQ)2PYR or (DHQD)2PYR ligands leads to preferences for diols 7 or 8 respectively.
- Gardiner, John M.,Bruce, Sarah E.
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p. 1029 - 1032
(2007/10/03)
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- Intermolecular Diastereoselective Nitrile Oxide Addition With Propargylic Ethers
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With simple and stereogenic propargylic ethers 3,4,5,7 and 11, cycloaddition reactions of the nitrile oxide 2 are performed in moderately high yield and with considerable regioselectivity.
- Baskaran, Subramanian,Baskaran, Chitra,Trivedi, Girish K.
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p. 2459 - 2471
(2007/10/03)
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- Enantiospecific syntheses of (R)- and (S)-proline and some derivatives from D-glucono-1,5-lactone
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Carbohydrate-based enantiospecific syntheses of (R)-proline 1 and (S)-proline 2 from the previously reported D-erythro-hexonate ester 9 are described. Azide-substitution reactions on appropriately activated intermediates derived from ester 9, followed by reductive cyclization (H2/Pd-C), gave the substituted pyrrolidines 14 and 22, which were converted into their corresponding N-Cbz derivatives 16 and 24 in conventional manner. Mild acidic hydrolysis of these, followed by oxidation (sodium metaperiodate), gave the protected prolinals 3 and 4, which on further oxidation (sodium chlorite), followed by catalytic hydrogenolysis, gave the prolines 1 and 2. The N-Cbz-prolinol derivatives 5 and 6 are also reported.
- Mazzini, Claudio,Sambri, Letitia,Regeling, Henk,Zwanenburg, Binne,Chittenden, Gordon J. F.
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p. 3351 - 3356
(2007/10/03)
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- Synthesis and application of ligands for the asymmetric addition of organolithium reagents to imines
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Amino acid derived ligands 4d,e are prepared from (S)-valine and (S)-proline respectively, and can be used as chiral ligands during the asymmetric addition of organolithium reagents to N-arylimines. Ligand 4e, which is prepared by two independent routes, is found to induce addition of organolithium reagents to the si-face of the imines, whilst ligand 4d in common with the previously reported catalysts 4a-c induces addition to the re-face of the imines.
- Jones, Catrin A.,Jones, Iwan G.,Mulla, Mushtaq,North, Michael,Sartori, Lucia
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p. 2891 - 2896
(2007/10/03)
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- Method of preparing enantiomerically-pure 3-methyl-5-(1-alkyl-2(s)-pyrrolidinyl)isoxazoles
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A novel process for preparing enantiomerically-pure 3-methyl-5-(1-(C1 -C3 -alkyl)-2-pyrrolidinyl)isoxazole in high yield, wherein a protected 2-oxo-pyrrolidine starting material is reacted with a suitable organic anion and a resulting beta-keto oxime intermediate is cyclized and dehydrated.
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- Intermediates for the preparation of enantiomerically-pure-3-methyl-5-(1-C1-C3-alkyl)-2-pyrrolidinyl)isoxazole
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Novel compounds useful in the preparation of enantiomerically-pure 3-methyl-5-(1-(C1 -C3 -alkyl)-2-pyrrolidinyl)isoxazole in high yield, namely 5(S)-(3-methyl-5-isoxazolyl)-2-pyrrolidinone, 3-methyl-5-(1-methyl-2-pyrrolidinyl)-5-hydroxy-4,5-dihydro-isoxazole, and 1-(1-methyl-2(S)-pyrrolidinyl)-1,3-butanedione-3-oxime.
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- Catalytic antibodies in synthesis: Design and synthesis of a hapten for application to the preparation of a scalemic pyrrolidine ring synthon for ptilomycalin A
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A catalytic antibody-based approach toward the synthesis of an optically active pyrrolidine ring synthon potentially useful for ptilomycalin A is described. Enantiomerically pure hapten 37 was designed and constructed with the eventual goal of generating antibodies for the enantioselective partial hydrolysis of a mesoo diester such as 44 into a monoacid 45. This transition state analog possesses a phosphonate group containing the requisite oxyanionic character of the tetrahedral intermediate for ester hydrolysis. A newly developed carbamate-based linker, which was found to be much more hydrolytically stable than the commonly used glutarate ester, was developed for coupling of the hapten to a carrier protein.
- Anderson, Glen T.,Alexander, Michael D.,Taylor, Scott D.,Smithrud, David B.,Benkovic, Stephen J.,Weinreb, Steven M.
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p. 125 - 132
(2007/10/03)
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- SUBSTITUTED OXOTREMORINE DERIVATIVES
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This disclosure describes novel substituted oxotremorine derivatives of formula I having nitrogen, oxygen or sulfur groups and the prodrug forms of these derivatives. The compounds have cholinergic activity. Also disclosed are methods for treating diseases of the central nervous system in mammals employing the compounds, pharmaceutical preparations containing the compounds and the processes for the production of the compounds. STR1
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- Synthesis of sequence-selective C8-linked pyrrolo[2,1-c][1,4]benzodiazepine DNA interstrand cross-linking agents
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An efficient convergent synthesis of a homologous series of C8-linked pyrrolobenzodiazepine dimers with remarkable DNA interstrand cross-linking activity and potent in vitro cytotoxicity is reported. The 'amino thioacetal' cyclization procedure was used t
- Thurston, David E.,Bose, D. Subhas,Thompson, Andrew S.,Howard, Philip W.,Leoni, Alberto,Croker, Stephen J.,Jenkins, Terrence C.,Neidle, Stephen,Hartley, John A.,Hurley, Laurence H.
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p. 8141 - 8147
(2007/10/03)
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