- Practical synthesis of (S)-pyrrolidin-2-yl-1H-tetrazole, incorporating efficient protecting group removal by flow-reactor hydrogenolysis
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A practical, safe, high-yielding and efficient synthesis of (S)-pyrrolidin-2-yl-1H-tetrazole has been developed, which avoids the generation of ammonium azide in the cyclisation step and the use of a 9:1 acetic acid-water mixture as the solvent in the hydrogenation. The previously extended hydrogenolysis reaction time (three days) is now reduced to hours through the use of an H-Cube (a continuous-flow reactor employing a mixed hydrogen-liquid flow stream). Georg Thieme Verlag Stuttgart.
- Franckevi?ius, Vilius,Knudsen, Kristian Rahbek,Ladlow, Mark,Longbottom, Deborah A.,Ley, Steven V.
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Read Online
- An expedient route to the tetrazole analogues of α-amino acids
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(Matrix presented) Convenient conditions are described for the transformation of α-aminonitriles to the tetrazole analogues of α-amino acids. Refluxing the starting material in water/2-propanol at 80 °C with sodium azide and catalytic zinc bromide affords
- Demko, Zachary P.,Sharpless, K. Barry
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Read Online
- Glycosylation mediated - BAIL in aqueous solution
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The use of Br?nsted acid ionic liquid (BAIL) as a catalyst for the activation of unreactive and unprotected glycosyl donors has been demonstrated for the first time in aqueous solution.
- Delacroix, Sébastien,Bonnet, Jean-Pierre,Courty, Matthieu,Postel, Denis,Van Nhien, Albert Nguyen
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- USE OF AZIDES IN SYNTHESIS
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Described herein are inventive methods for synthesis of tetrazoles. In some embodiments, the method involves the use of a flow reactor. The methods provided herein are capable at being carried out in short reaction times, with high yields, with minimal side reactions, and/or with minimal chance of explosions caused by the presence of azides.
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Page/Page column 16-26
(2012/03/11)
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- Enantioselective total synthesis of (S)-(+)-lennoxamine through asymmetric hydrogenation mediated by l-proline-tetrazole ruthenium catalyst
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A novel asymmetric synthetic strategy to prepare isoindolobenzazepine based lennoxamine alkaloid has been achieved in high ee% starting from 2-(benzo[d][1,3]dioxol-5-yl)ethanamine and 1-(chloromethyl)-2,3-dimethoxybenzene in 5 steps and with a 34% overall yield. The potentiality of this route involved the Bischler-Napieralsky cyclization that leads to tetracyclic indolinium skeleton, generation of chiral center through asymmetric hydrogen-transfer reaction employing l-proline-tetrazole as chiral ligand with Ru/Ir/Rh, and anodic oxidation as the key steps in the synthesis.
- Mirabal-Gallardo, Yaneris,Piérola, Johanna,Shankaraiah, Nagula,Santos, Leonardo S.
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scheme or table
p. 3672 - 3675
(2012/10/07)
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- Safe and efficient tetrazole synthesis in a continuous-flow microreactor
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Safer flow: The synthesis of 5-substituted tetrazoles in flow (see scheme) is safe, efficient, scalable, requires no metal promoter, and uses a near-equimolar amount of NaN3, yet nonetheless displays a broad substrate scope. The hazards associated with HN3 are essentially eliminated, shock-sensitive metal azides such as Zn(N3)2 are avoided, and residual NaN3 is quenched in-line with NaNO 2. Copyright
- Palde, Prakash B.,Jamison, Timothy F.
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supporting information; experimental part
p. 3525 - 3528
(2011/05/04)
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- Pyrrolidine amides of pyrazolodihydropyrimidines as potent and selective KV1.5 blockers
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Design and synthesis of pyrazolodihydropyrimidines as KV1.5 blockers led to the discovery of 7d as a potent and selective antagonist. This compound showed atrial selective prolongation of effective refractory period in rabbits and was selected for clinical development.
- Lloyd, John,Finlay, Heather J.,Vacarro, Wayne,Hyunh, Tram,Kover, Alexander,Bhandaru, Rao,Yan, Lin,Atwal, Karnail,Conder, Mary Lee,Jenkins-West, Tonya,Shi, Hong,Huang, Christine,Li, Danshi,Sun, Huabin,Levesque, Paul
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scheme or table
p. 1436 - 1439
(2010/07/02)
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- Synthesis of substituted 5-(pyrrolidin-2-yl)tetrazoles and their application in the asymmetric Biginelli reaction
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A series of chiral substituted 5-(pyrrolidin-2-yl)tetrazoles have been synthesized and evaluated as organocatalysts for the asymmetric Biginelli reaction. The relationship between catalytic activity and the different catalyst structures is briefly discussed. By using the optimized catalyst C10 (10 mol-%), a series of 3,4-dihydropyrimidin-2(1H)-one (DHPM) derivatives have been obtained in 63-88% yields and 68-81 % ee values within 24 h at room temperature.
- Wu, Yong-Yong,Chai, Zhuo,Liu, Xin-Yuan,Zhao, Gang,Wang, Shao-Wu
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experimental part
p. 904 - 911
(2009/07/19)
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- PDF INHIBITORS
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The invention relates to novel compounds that are inhibitors of peptidyl deformylase (PDF). The compounds are useful as antimicrobials and antibiotics. The compounds of the invention display selective inhibition of peptidyl deformylase versus other metalloproteinases such as MMPs. Methods of preparation and uses of the compounds are also disclosed.
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- 1,3-Dipolar cycloaddition: Click chemistry for the synthesis of 5-substituted tetrazoles from organoaluminum azides and nitriles
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Cheap and safe: Conventional methods to prepare tetrazoles employ dangerous, toxic reagents. A new route to these heterocycles (see scheme) uses inexpensive and nontoxic dialkyl aluminum azides. The cycloaddition occurs under mild conditions and tolerates a variety of functional groups. The low cost and ecocompatibility make this process attractive for large-scale preparation. (Chemical Equation Presented).
- Aureggi, Valentina,Sedelmeier, Gottfried
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p. 8440 - 8444
(2008/09/19)
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- PEPTIDE DEFORMYLASE INHIBITORS
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Novel PDF inhibitors of formulas (I) and (II), pharmaceutical compositions thereof and methods for their use in the treatment of bacterial infections are described.
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Page/Page column 14; 24-25
(2010/11/27)
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- PREPARATION OF TERAZOLE DERIVATIVES
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The invention relates to a process for the preparation of (S)-pyrrolidine-1H-tetrazole derivatives of formula (I), wherein R1, R2 and R3, independently of one another, represent hydrogen, halogen or an organic radical, in
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Page/Page column 30
(2010/11/25)
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- Microwave-assisted one-pot tandem reactions for direct conversion of primary alcohols and aldehydes to triazines and tetrazoles in aqueous media
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(Chemical Equation Presented) A series of primary alcohols and aldehydes were treated with iodine in ammonia water under microwave irradiation to give the intermediate nitriles, which without isolation underwent [2 + 3] cycloadditions with dicyandiamide and sodium azide to afford high yields of the corresponding triazines and tetrazoles, including the α-amino- and dipeptidyl tetrazoles in high optical purity.
- Shie, Jiun-Jie,Fang, Jim-Min
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p. 3141 - 3144
(2008/02/13)
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- 5-(Pyrrolidine-2-yl)tetrazole: Rationale for the increased reactivity of the tetrazole analogue of proline in organocatalyzed aldol reactions
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5-[(2S)-Pyrrolidine-2-yl]-1H-tetrazole (1), i.e. the tetrazolic acid analogue of proline, has been found to be significant more reactive than L-proline (2) in various organocatalyzed reactions. In the organocatalyzed direct asymmetric aldol reaction, acetone was reacted with aromatic and aliphatic aldehydes to afford the resulting β-hydroxy ketones in good yields and moderate to high enantiomeric excesses. The increased reactivity of 1, as compared to 2, has been rationalized through a combined computational and NMR spectroscopic study. It was found that catalyst 2 was almost completely engaged in oxazolidinone formation with the aldehyde whereas 1 did not take part in such parasitic equilibrium. This finding, together with the improved solubility of the tetrazole analogue, is proposed to account for the observed reactivity. Wiley-VCH Verlag GmbH & Co. KGaA, 2005.
- Hartikka, Antti,Arvidsson, Per I.
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p. 4287 - 4295
(2007/10/03)
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- Organocatalysis with proline derivatives: Improved catalysts for the asymmetric Mannich, nitro-Michael and aldol reactions
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Tetrazole and acylsulfonamide organocatalysts derived from proline have been synthesised and applied to the asymmetric Mannich, nitro-Michael and aldol reactions to give results that are superior to the proline-catalysed counterpart.
- Cobb, Alexander J. A.,Shaw, David M.,Longbottom, Deborah A.,Gold, Johan B.,Ley, Steven V.
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- VLA-4 INHIBITOR
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A compound which selectively inhibits bonding between a ligand and α4β1 integrin (VLA-4); a process for producing the compound; and a medicine containing the compound. The compound is one represented by, e.g., the formula (I) or a salt thereof. Also provided is a preventive and/or therapeutic agent which contains the compound or salt as a major component and is effective against diseases attributable to cell adhesion, such as, e.g., inflammatory reaction, autoimmune disease, cancer metastasis, bronchial asthma, nasal obstruction, diabetes, arthritis, psoriasis, multiple sclerosis, inflammatory intestinal disease, and rejection reaction in transplantation. (In the formula, Y1 represents arylene, etc.; V1 represents aryl, etc.; and R11 to R14 each represents H, OH, halogeno, etc.)
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- Rational design of asymmetric organocatalysts - Increased reactivity and solvent scope with a tetrazolic acid
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Replacement of the carboxylic acid functionality in the widely used organocatalyst proline with a tetrazolic acid leads to a catalyst with increased reactivity and solvent scope, as demonstrated in the direct catalytic asymmetric aldol reaction.
- Hartikka, Antti,Arvidsson, Per I.
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p. 1831 - 1834
(2007/10/03)
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- 5-Pyrrolidin-2-yltetrazole: A New, Catalytic, More Soluble Alternative to Proline in an Organocatalytic Asymmetric Mannich-type Reaction
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A Mannich-type addition of ketones to N-PMP protected α-imino ethyl glyoxalate is catalyzed by a new proline analogue, 5-pyrrolidin-2-yltetrazole 1. The new organocatalyst has significant advantage over its parent in that it can be used in non-polar solvents without loss of enantioselectivity.
- Cobb, Alexander J. A.,Shaw, David M.,Ley, Steven V.
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p. 558 - 560
(2007/10/03)
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- Synthesis and biological activity of carboxylic acid replacement analogues of the potent angiotensin converting enzyme inhibitor 5(S)-benzamido-4-oxo-6-phenylhexanoyl-L-proline
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The carboxylic acid group on the proline of the ketomethylene analog of the tripeptide Bz-Phe-Gly-Pro 1 was replaced by a phosphoric acid, a hydroxamic acid, and a tetrazole to give compounds 2-4, respectively. Testing of 2-4 as angiotensin converting enz
- Almquist,Chao,Jennings-White
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p. 1067 - 1071
(2007/10/02)
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