101
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Posner PG, Motherwell PW. Tetrahedron reports on organic chemistry. Tetrahedron 2004. [DOI: 10.1016/s0040-4020(04)01396-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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102
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Reutrakul V, Thongpaisanwong T, Tuchinda P, Kuhakarn C, Pohmakotr M. Difluorophenylsulfanylmethyl Radical and Difluoromethylene Diradical Synthons: gem-Difluoromethylene Building Block. J Org Chem 2004; 69:6913-5. [PMID: 15387624 DOI: 10.1021/jo0489768] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Bromodifluorophenylsulfanylmethane has been demonstrated to be a highly versatile gem-difluoromethylene (CF2) building block via the reaction of difluorophenylsulfanylmethyl radical with olefins. gem-Difluoroalkenes and products containing a midchain CF2 group and with manipulatable functionality can be readily synthesized. The first example of a gem-difluoromethylene radical synthon is also reported.
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Affiliation(s)
- Vichai Reutrakul
- Department of Chemistry, Faculty of Science, Mahidol University, Rama 6 Road, Bangkok 10400, Thailand.
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103
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Chen X, Zhou W, Schinazi RF, Chu CK. Synthesis of 3‘-Fluoro-2‘,3‘-dideoxy-2‘,3‘-didehydro-4‘-ethynyl-d- and -l-furanosyl Nucleosides. J Org Chem 2004; 69:6034-41. [PMID: 15373488 DOI: 10.1021/jo049597h] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
An efficient procedure has been developed for the synthesis of 3'-fluoro-2',3'-dideoxy-2',3'-didehydro-4'-ethynyl D- and L-furanosyl nucleosides (1 and 2) starting from 2,3-O-isopropylidene-d-glyceraldehyde. The key intermediate 1-O-benzoyl-3E-fluoro-3,4-unsaturated-5,6-di(tert-butyldimethylsilyloxy)-2-hexanone 8 was obtained in nine steps with the overall yield of 22%. The alpha,beta-unsaturated ketone 8 was then treated with ethynylmagnesium bromide in a typical Grignard reaction procedure to afford the two intermediates 9 and 10, which after deprotection, oxidation, and acetylation gave the corresponding 4-ethynyl-substituted D- and L-sugar moieties 15 and 16, respectively. A series of D- and L-pyrimidine and purine nucleosides were prepared by the coupling of the sugar moieties with various silylprotected bases. The anomeric mixtures were obtained after condensation. After separation, the beta-isomers were further deprotected to yield the target nucleosides. All the newly synthesized 4'-substituted nucleosides were tested for their activities against HIV, among which the D-adenine derivative showed moderate anti-HIV activity (EC(50) = 25.1 microM) without significant cytotoxicity.
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Affiliation(s)
- Xin Chen
- College of Pharmacy, The University of Georgia, Athens, Georgia 30602, USA
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104
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Amino alcohol catalyzed direct asymmetric aldol reactions: enantioselective synthesis of anti -α-fluoro-β-hydroxy ketones. Tetrahedron Lett 2004. [DOI: 10.1016/j.tetlet.2004.05.107] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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105
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Colin T, El Kaı̈m L, Gaultier L, Grimaud L, Gatay L, Michaut V. New access to fluorinated ketoglycolic acid derivatives from trifluoropyruvamides. Tetrahedron Lett 2004. [DOI: 10.1016/j.tetlet.2004.05.128] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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106
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Itoh T, Ishida N, Mitsukura K, Hayase S, Ohashi K. Synthesis of optically active gem-difluorocyclopropanes through a chemo-enzymatic reaction strategy. J Fluor Chem 2004. [DOI: 10.1016/j.jfluchem.2004.01.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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107
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Pesenti C, Viani F. The Influence of Fluorinated Molecules (Semiochemicals and Enzyme Substrate Analogues) on the Insect Communication System. Chembiochem 2004; 5:590-613. [PMID: 15122631 DOI: 10.1002/cbic.200300829] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Can the introduction of fluorine atoms affect the bioactivity of natural semiochemicals? Can fluorine contribute in the creation of specific enzyme inhibitors to interrupt or disrupt the insect communication system? The first step for the bioactivity of a molecule is interaction with the biological sensor. Hydrogen and fluorine are almost bioisosteric and the receptor site of the enzyme can still recognize and accept the fluoro analogue of its natural substrate. However, the peculiar electronegativity of the fluorine atom can affect the binding, absorption, and transport of the molecule. The differences in the molecule's electronic properties can lead to differences in the chemical interactions between the receptor and the fluorinated substrate. Fluorine introduction can modify the metabolic stability and pathway of the semiochemicals in many different ways. Fluorinated analogues can show synergism, inhibition, or hyperagonism effects on insect behaviors, that is, the activity of the nonfluorinated parent compounds can be mimicked, lost, or increased. In any case, the fluorinated molecules can interact with the bioreceptors in a new and disrupting way. The semiochemicals are olfactory substances: fluorine can affect their volatility or smell. Production of semiochemicals from exogenous substances, perception at antennal receptors, and processing of biological responses are the main steps of communication among insects. In the production step, the fluorinated molecules can interact with enzymes that catalyze the biosynthesis of the natural pheromones. In the perception step, fluorinated semiochemicals can interact with the olfactory receptor cells; this often leads to totally unpredictable behaviors. Fluorinated molecules have been developed as probes to elucidate the complex chemorecognition processes of insects. Many of these molecules have been tested to find highly effective behavior-modifying chemicals. New analogues have been synthesized to investigate the metabolic pathway of a pheromone molecule and many of them are promising disrupting agents. Despite such titanic research efforts, the results have often been random, rational trends in the induced behaviors have sometimes been impossible to find, and practical applications of the fluorinated semiochemicals are still uncertain.
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Affiliation(s)
- Cristina Pesenti
- Istituto di Chimica per il Riconoscimento Molecolare, Consiglio Nazionale delle Ricerche, Via Mancinelli 7, 20131 Milano, Italy
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108
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Tetrahedron reports on organic chemistry. Tetrahedron 2004. [DOI: 10.1016/s0040-4020(04)00315-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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109
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Diastereoselective formation of 2-fluoro-2-trifluoromethyl-3,4-alkadienamides from propargyl alcohols and hexafluoropropene–diethylamine adduct (PPDA). J Fluor Chem 2004. [DOI: 10.1016/j.jfluchem.2003.11.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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110
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Zani F, Vicini P, Incerti M. Synthesis and antimicrobial properties of 2-(benzylidene-amino)-benzo[d]isothiazol-3-ones. Eur J Med Chem 2004; 39:135-40. [PMID: 14987822 DOI: 10.1016/j.ejmech.2003.11.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2003] [Accepted: 11/07/2003] [Indexed: 10/26/2022]
Abstract
The in vitro antimicrobial activity of 2-amino-benzo[d]isothiazol-3-one and of several 2-arylideneamino derivatives carrying in the second position a substituted or unsubstituted aromatic ring or an arylalkenylidene moiety was determined by the broth dilution method against several strains selected to define their spectrum and potency. All the compounds demonstrated good antibacterial properties against Bacillus subtilis, streptococci, enterococci and staphylococci including penicillin-resistant clinical isolates. Several compounds showed excellent inhibitory properties against Streptococcus pyogenes, which is the most sensitive microorganism tested. Many benzisothiazolones exhibited good activity against Gram-negative Haemophilus influenzae. As regards antifungal activity, several of the tested compounds inhibited Saccharomyces cerevisiae at concentrations of 3-6 microg ml-1. In all cases the parent 2-amino-benzo[d]isothiazol-3-one was the most effective agent, with minimum inhibitory concentration (MIC) values ranging from 0.07 to 6 microg ml-1. The results obtained indicate that most of these compounds are wide-spectrum antimicrobial substances and promising agents against penicillin-resistant staphylococci.
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Affiliation(s)
- Franca Zani
- Dipartimento Farmaceutico, Università degli Studi di Parma, Parco Area delle Scienze 27/A, 43100 Parma, Italy.
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111
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112
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Harper JB, Lynden-Bell RM. Macroscopic and microscopic properties of solutions of aromatic compounds in an ionic liquid. Mol Phys 2004. [DOI: 10.1080/00268970410001668570] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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113
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α-Fluoroacrylonitriles: Horner–Wittig synthesis and conversion into 2-fluoroallylamines and C-(1-fluorovinyl)nitrones. J Fluor Chem 2004. [DOI: 10.1016/j.jfluchem.2003.11.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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114
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115
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Shen Y, Li P. Stereoselective synthesis of trifluoromethylated vinyl- and dienylphosphonates with γ-alkoxycarbonyl moiety. J Fluor Chem 2004. [DOI: 10.1016/j.jfluchem.2003.10.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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116
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Posner PG, Motherwell PW. Tetrahedron reports on organic chemistry. Tetrahedron 2003. [DOI: 10.1016/s0040-4020(03)01884-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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117
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Ogu KI, Akazome M, Ogura K. A novel reaction of allylic alcohols with hexafluoropropene-diethylamine adduct (PPDA) to form 2-fluoro-2-trifluoromethyl-4-alkenamide. J Fluor Chem 2003. [DOI: 10.1016/s0022-1139(03)00191-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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118
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Kobayashi T, Nakagawa T, Amii H, Uneyama K. Mg-Promoted Double Silylation of Trifluoroacetimidoyl Chlorides. A New Entry to the Fluorinated Dianion Equivalents. Org Lett 2003; 5:4297-300. [PMID: 14601984 DOI: 10.1021/ol035528y] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
[reaction: see text] A Mg(0)/Me(3)SiCl system was found to be effective for the preparation of a novel fluorinated dianion equivalent. A one-pot reaction sequence involving reductive C-F and C-Cl bond cleavage reactions of trifluoroacetimidoyl chlorides afforded bis-silylated difluoroenamines. Subsequent carbon-carbon bond-forming reactions of the bis(silyl)enamines with two kinds of electrophiles gave a variety of difluorinated imines.
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Affiliation(s)
- Takeshi Kobayashi
- Department of Applied Chemistry, Faculty of Engineering, Okayama University, 3-1-1 Tsushimanaka, Okayama 700-8530, Japan
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119
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Jiang J, Shah H, DeVita RJ. Synthesis of 4-Trifluoromethylated 2-Alkyl- and 2,3-Dialkyl-Substituted Azetidines. Org Lett 2003; 5:4101-3. [PMID: 14572259 DOI: 10.1021/ol030099p] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
[reaction: see text]. A diastereoselective approach to the synthesis of 4-trifluoromethylated 2-alkyl- and 2,3-dialkylazetidines, including BOC-protected 4-trifluoromethylazetidin-2-ylcarboxylic acid, was developed via Wittig reaction of 4-trifluomethylated beta-lactam followed by alkylation and hydrogenation.
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Affiliation(s)
- Jinlong Jiang
- Department of Medicinal Chemistry, Merck Research Laboratory, P.O. Box 2000, Rahway, New Jersey 07065, USA.
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120
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Prakesch M, Grée D, Grée R. Synthesis and reactivity of Z and E functionalized allylic fluorides. Tetrahedron 2003. [DOI: 10.1016/j.tet.2003.08.068] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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121
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Jiang ZX, Qin YY, Qing FL. Asymmetric synthesis of both enantiomers of anti-4,4,4-trifluorothreonine and 2-amino-4,4,4-trifluorobutanoic acid. J Org Chem 2003; 68:7544-7. [PMID: 12968918 DOI: 10.1021/jo0344384] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A short and efficient enantioselective synthesis of both enantiomers of anti-4,4,4-trifluorothreonine and 2-amino-4,4,4-trifluorobutanoic acid was successfully developed. Trifluoromethylation of benzyl-protected bromoalkene 4 provided key intermediate trifluoromethylated trans-disubstituted alkene 2 in good yield. The sequence then involved Sharpless asymmetric dihydroxylation, nucleophilic opening of cyclic sulfate with NaN(3), palladium-catalyzed selective hydrogenation, and oxidation.
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Affiliation(s)
- Zhong-Xing Jiang
- Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Science, 354 Fenglin Lu, Shanghai 200032, China
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122
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Ichikawa J, Fukui H, Ishibashi Y. 1-Trifluoromethylvinylsilane as a CF2C-−CH2+ Synthon: Synthesis of Functionalized 1,1-Difluoro-1-alkenes via Isolable 2,2-Difluorovinylsilanes. J Org Chem 2003; 68:7800-5. [PMID: 14510558 DOI: 10.1021/jo034718j] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Various 1,1-difluoro-1-alkenes such as monosubstituted 1,1-difluoro-1-alkenes, 2-bromo-1,1-difluoro-1-alkenes, and 3,3-difluoroallylic alcohols are synthesized in two simple steps from 1-trifluoromethylvinylsilane: (i) its SN2' reaction with nucleophiles to construct 2,2-difluorovinylsilanes and (ii) the subsequent substitution of electrophiles for the vinylic silyl group. The combination of these two processes allows a one-pot synthesis of the functionalized 1,1-difluoro-1-alkenes starting from 1-trifluoromethylvinylsilane, which functions as a CF2=C(-)-CH2+ synthon.
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Affiliation(s)
- Junji Ichikawa
- Department of Chemistry, Graduate School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
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123
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Yajima T, Nagano H, Saito C. Radical-mediated hydroxytrifluoromethylation of α,β-unsaturated esters. Tetrahedron Lett 2003. [DOI: 10.1016/s0040-4039(03)01783-0] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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124
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Posner PG, Motherwell PW. Tetrahedron reports on organic chemistry. Tetrahedron 2003. [DOI: 10.1016/s0040-4020(03)01130-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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125
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Chirakul P, Sigurdsson ST. Unexpected formation of 2′-deoxy-N3-(3,3,3-trifluoro-1-propenyl)uridine via a Michael-type addition to 3,3,3-trifluoropropyne. Tetrahedron Lett 2003. [DOI: 10.1016/s0040-4039(03)01702-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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126
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127
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Vu NQ, Grée D, Grée R, Brown E, Dujardin G. Regiocontrolled fluorination of 2-hydroxyalkyl dihydropyrans and carbonyl derivatives. Tetrahedron Lett 2003. [DOI: 10.1016/s0040-4039(03)01601-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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128
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Chen Y, Huang L, Zhang XP. Efficient and stereoselective synthesis of beta-trifluoromethyl alpha,beta-unsaturated esters via iron(III) porphyrin-catalyzed olefination of ketones. J Org Chem 2003; 68:5925-9. [PMID: 12868927 DOI: 10.1021/jo034509z] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
beta-Trifluoromethyl alpha,beta-unsaturated esters were efficiently prepared by reactions of fluorine-containing ketones with diazo compounds via metalloporphyrin-catalyzed olefination in the presence of triphenylphosphine. The commercially available Fe(III)(TPP)Cl (TPP: tetraphenylporphyrin) is effective for catalyzing the olefination of a variety of trifluoromethyl ketones with different diazoacetate esters under mild conditions. The reactions proceeded with high yields (up to 95% isolated yield) and high stereoselectivity (up to 99% (E)-selectivity).
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Affiliation(s)
- Ying Chen
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996-1600, USA
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129
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Matsuda T, Kanamaru R, Watanabe K, Kamitanaka T, Harada T, Nakamura K. Control of enantioselectivity of lipase-catalyzed esterification in supercritical carbon dioxide by tuning the pressure and temperature. ACTA ACUST UNITED AC 2003. [DOI: 10.1016/s0957-4166(03)00431-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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130
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Abstract
Two fluorinated derivatives of isoleucine: d,l-2-amino-3-trifluoromethyl pentanoic acid (3TFI, 2) and d,l-2-amino-5,5,5-trifluoro-3-methyl pentanoic acid (5TFI, 3) were prepared. 5TFI was incorporated into a model target protein, murine dihydrofolate reductase (mDHFR), in an isoleucine auxotrophic Escherichia coli host strain suspended in 5TFI-supplemented minimal medium depleted of isoleucine. Incorporation of 5TFI was confirmed by tryptic peptide analysis and matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) of the protein product. Amino acid analysis showed that more than 93% of the encoded isoleucine residues were replaced by 5TFI. Measurement of the rate of activation of 5TFI by the E. coli isoleucyl-tRNA synthetase (IleRS) yielded a specificity constant (k(cat)/K(m)) 134-fold lower than that for isoleucine. 5TFI was successfully introduced into the cytokine murine interleukin-2 (mIL-2) at the encoded isoleucine positions. The concentration of fluorinated protein that elicits 50% of the maximal proliferative response is 3.87 ng/mL, about 30% higher than that of wild-type mIL-2 (EC(50) = 2.70 ng/mL). The maximal responses are equivalent for the fluorinated and wild-type cytokines, indicating that fluorinated proteins can fold into stable and functional structures. 3TFI yielded no evidence for in vivo incorporation into recombinant proteins, and no evidence for activation by IleRS in vitro.
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Affiliation(s)
- Pin Wang
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA
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131
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Itoh T, Ishida N, Ohashi M, Asep R, Nohira H. Synthesis of Novel Liquid Crystals which Possessgem-Difluorocyclopropane Moieties. CHEM LETT 2003. [DOI: 10.1246/cl.2003.494] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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132
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Posner PG, Motherwell PW. Tetrahedron reports on organic chemistry. Tetrahedron 2003. [DOI: 10.1016/s0040-4020(03)00841-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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133
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Tetrahedron reports on organic chemistry. Tetrahedron 2003. [DOI: 10.1016/s0040-4020(03)00323-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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134
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Brazzarola F, Tubaro M, Bravo P, Zanda M, Volonterio A, Traldi P. The mass spectrometric behaviour of fluorinated ephedrines under different protonating conditions. FARMACO (SOCIETA CHIMICA ITALIANA : 1989) 2003; 58:69-77. [PMID: 12595039 DOI: 10.1016/s0014-827x(02)00028-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The behaviour of di- and tri-fluorinated-ephedrines and -norephedrines has been studied by fast atom bombardment, atmospheric pressure chemical ionisation (APCI) and electrospray ionisation (ESI) experiments and compared with that of the unfluorinated analogues. Under all the employed ionisation conditions [MH](+) and [MH-H(2)O](+) species are mainly produced. Both high- and low-energy collisional experiments were performed on the protonated molecules to put in evidence any possible significant differences due to different ionisation methods. Multiple MS/MS experiments, performed by ion trap, allowed establishment of the decomposition pathways at lower activation energy. The data thus obtained indicate that the presence of fluorinated substituents leads to a higher stability of the molecular species, with strengthening of the C(1)-C(2) bond of the molecule and with a lower proclivity to thermally-induced dehydration.
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Affiliation(s)
- Franco Brazzarola
- CNR, ISTM, Laboratorio di Ricerche in Spettrometria di Massa, Corso Stati Uniti 4, I35100 Padua, Italy
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135
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Posner G, Motherwell W. Tetrahedron reports on organic chemistry. Tetrahedron 2002. [DOI: 10.1016/s0040-4020(02)01503-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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136
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Takamatsu S, Katayama S, Hirose N, De Cock E, Schelkens G, Demillequand M, Brepoels J, Izawa K. Convenient synthesis of fluorinated nucleosides with perfluoroalkanesulfonyl fluorides. NUCLEOSIDES, NUCLEOTIDES & NUCLEIC ACIDS 2002; 21:849-61. [PMID: 12537026 DOI: 10.1081/ncn-120016572] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Perfluoroalkanesulfonyl fluorides are effective dehydroxy-fluorination agents for the hydroxyl group at the sugar moiety of nucleoside derivatives and give the corresponding fluorinated nucleosides in good yield with an inversion of configuration in a single step.
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Affiliation(s)
- Satoshi Takamatsu
- AminoScience Laboratories, Ajinomoto Co., Inc., 1-1, Suzuki-cho, Kawasaki-ku, Kawasaki 210-8681, Japan.
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137
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Shen Y, Zhang Y, Sun J. Regiospecific synthesis of perfluoroalkylated pyrrolo[2,1-a]isoquinolinyl phosphonates. J Fluor Chem 2002. [DOI: 10.1016/s0022-1139(02)00124-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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138
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Shen Y, Wang G. New polyfluorinated organotin reagents. Stereoselective synthesis of (Z)-alpha-fluoro-beta-trifluoromethylvinylstannanes. Org Lett 2002; 4:2083-5. [PMID: 12049523 DOI: 10.1021/ol0200697] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
[reaction: see text] A new methodology for the synthesis of (Z)-alpha-fluoro-beta-trifluoromethylvinylstannanes, which are useful polyfluorinated organotin reagents for the synthesis of fluorine-containing biologically active compounds, is described.
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Affiliation(s)
- Yanchang Shen
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Academia Sinica, Shanghai 200032, China.
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139
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140
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Haufe G, Rosen TC, Meyer OG, Fröhlich R, Rissanen K. Synthesis, reactions and structural features of monofluorinated cyclopropanecarboxylates. J Fluor Chem 2002. [DOI: 10.1016/s0022-1139(02)00040-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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141
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Konno T, Nagata K, Ishihara T, Yamanaka H. Concise syntheses of nonracemic gamma-fluoroalkylated allylic alcohols and amines via an enantiospecific palladium-catalyzed allylic substitution reaction. J Org Chem 2002; 67:1768-75. [PMID: 11895391 DOI: 10.1021/jo011013d] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Alpha-fluoroalkylated allyl mesylates reacted with various carboxylates and amines in the presence of tetrakis(triphenylphosphine)palladium(0) catalyst to give the corresponding gamma-fluoroalkylated (E)-allylic alcohol derivatives and amines, respectively, in excellent yields. In almost all cases, no other regio- and stereoisomers were produced. Application of this palladium-catalyzed allylic substitution reaction to various nonracemic mesylates afforded chiral gamma-fluoroalkylated allylic alcohol derivatives and amines without any loss of enantiomeric excess through the reaction.
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Affiliation(s)
- Tsutomu Konno
- Department of Chemistry and Materials Technology, Kyoto Institute of Technology, Sakyo-ku, Matsugasaki, Kyoto 606-8585, Japan.
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142
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Xing X, Fichera A, Kumar K. A simple and efficient method for the resolution of all four diastereomers of 4,4,4-trifluorovaline and 5,5,5-trifluoroleucine. J Org Chem 2002; 67:1722-5. [PMID: 11871915 DOI: 10.1021/jo011097q] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Xuechao Xing
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, USA
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143
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Okano T, Sugiura H, Fumoto M, Matsubara H, Kusukawa T, Fujita M. Copper(I)-catalyzed addition of trifluoromethylated benzyl radicals derived from aryltrifluoroethyl bromides to terminal olefins. J Fluor Chem 2002. [DOI: 10.1016/s0022-1139(02)00002-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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144
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145
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146
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Ambrosi P, Arnone A, Bravo P, Bruché L, De Cristofaro A, Francardi V, Frigerio M, Gatti E, Germinara GS, Panzeri W, Pennacchio F, Pesenti C, Rotundo G, Roversi PF, Salvadori C, Viani F, Zanda M. Stereoselective synthesis of trifluoro- and monofluoro-analogues of frontalin and evaluation of their biological activity. J Org Chem 2001; 66:8336-43. [PMID: 11735511 DOI: 10.1021/jo0055640] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The stereoselective synthesis of both enantiomers of trifluoro frontalin (-)-(1S,5R)- and (+)-(1R,5S)-8, as well as of diastereomeric monofluoro frontalines (-)-(1R,2R,5R)-18 and (-)-(1R,2S,5R)-20, analogues of the bioactive component of the aggregation pheromone of the Scolytidae insect family, has been accomplished starting from (-)-(1R)- and (+)-(1S)-menthyl (S)-toluene-4-sulfinate as a source of chirality and methyl trifluoroacetate or fluoroacetate, respectively, as sources of fluorine. The C-1 stereocenters were installed via stereoselective epoxidation of beta-sulfinyl ketones 2 and 13 with diazomethane. The bicyclic core was obtained by totally stereocontrolled and chemoselective tandem Wacker oxidation/intramolecular ketalization of the intermediate unsatured sulfinyl diols 5, 15, and 19. Axially fluorinated (-)-20 elicited a strong electroantennographic response in laboratory tests on females of Dendroctonus micans, whereas equatorially fluorinated (-)-18 and the trifluoroanalogue (-)-8 showed modest responses. Field trials using (-)-20 were not indicative owing to the locally scarce population of D. micans, but it showed some attractiveness for other Coleoptera families.
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Affiliation(s)
- P Ambrosi
- CNR, Centro di Studio sulle Sostanze Organiche Naturali, via Mancinelli 7, I-20131 Milano, Italy
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147
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Matsuda T, Kanamaru R, Watanabe K, Harada T, Nakamura K. Control on enantioselectivity with pressure for lipase-catalyzed esterification in supercritical carbon dioxide. Tetrahedron Lett 2001. [DOI: 10.1016/s0040-4039(01)01785-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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148
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Electrolytic partial fluorination of organic compounds. Part 57: Regioselective anodic monofluorination of nitrogen-containing heterocyclic propargyl sulfides. Tetrahedron 2001. [DOI: 10.1016/s0040-4020(01)00866-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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149
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Zhao G, Sun HL, Qian ZS, Yin WX. Cp2TiCl2(cat.)/Zn system promoted addition reaction of bromodifluoroacetate with the electron-deficient gem-dicyanoalkenes. J Fluor Chem 2001. [DOI: 10.1016/s0022-1139(01)00457-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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150
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Ding Y, Wang J, Abboud KA, Xu Y, Dolbier WR, Richards NG. Synthesis of L-4,4-difluoroglutamic acid via nucleophilic addition to a chiral aldehyde. J Org Chem 2001; 66:6381-8. [PMID: 11559190 DOI: 10.1021/jo015754q] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Fluorine-containing derivatives of amino acids are assuming increasing importance as probes of biological function and enzyme mechanism. We now report a new, flexible route to enantiomerically pure L-4,4-difluoroglutamic acid that exploits the addition of difluorinated nucleophiles to configurationally stable alpha-aminoaldehydes. Conversion of the difluorinated adducts to L-4,4-difluoroglutamic acid can be accomplished in three steps by Barton-McCombie dehydroxylation and acid hydrolysis.
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Affiliation(s)
- Y Ding
- Department of Chemistry, University of Florida, Gainesville, FL 32611-7200, USA
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