15877-57-3Relevant articles and documents
Mutual influence of backbone proline substitution and lipophilic tail character on the biological activity of simplified analogues of caspofungin
Mulder, Monique P. C.,Fodran, Peter,Kemmink, Johan,Breukink, Eefjan J.,Kruijtzer, John A. W.,Minnaard, Adriaan J.,Liskamp, Rob M. J.
, p. 7491 - 7502 (2012)
The echinocandins represent the most recent class of antifungal drugs. Previous structure-activity relationship studies on these lipopeptides have relied mainly upon semisynthetic derivatives due to their complex chemical structures. A successful strategy for the rapid enantioselective synthesis of the branched fatty acid chain of caspofungin and analogues was developed to synthesize several simplified analogues of caspofungin. The specific minimum inhibitory activity of each mimic was determined against a panel of Candida strains. This approach gave access to new fully synthetic derived caspofungin mimics with high and selective antifungal activities against Candida strains. In addition, the data suggested an important role of the hydroxy proline residue in the bioactive conformation of the macrocyclic peptide ring structure.
PROCESS FOR THE ALKOXYCARBONYLATION OF ETHERS
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Paragraph 0111, (2018/02/28)
The invention relates to a process comprising the following process steps: a) introducing an ether having 3 to 30 carbon atoms; b) adding a phosphine ligand and a compound which comprises Pd, or adding a complex comprising Pd and a phosphine ligand; c) adding an alcohol; d) supplying CO; e) heating the reaction mixture, the ether being reacted for form an ester; where the phosphine ligand is a compound of formula (I) where m and n are each independently 0 or 1; R1, R2, R3, R4 are each independently selected from —(C1-C12)-alkyl, —(C3-C12)-cycloalkyl, —(C3-C12)-heterocycloalkyl, —(C6-C20)-aryl, —(C3-C20)-heteroaryl; at least one of the R1, R2, R3, R4 radicals is a —(C3-C20)-heteroaryl radical; and R1, R2, R3, R4, if they are —(C1-C12)-alkyl, —(C3-C12)-cycloalkyl, —(C3-C12)-heterocycloalkyl, —(C6-C20)-aryl or —(C3-C20)-heteroaryl, may each independently be substituted by one or more substituents selected from —(C1-C12)-alkyl, —(C3-C12)-cycloalkyl, —(C3-C12)-heterocycloalkyl, —O—(C1-C12)-alkyl, —O—(C1-C12)-alkyl-(C6-C20)-aryl, —O—(C3-C12)-cycloalkyl, —S—(C1-C12)-alkyl, —S—(C3-C12)-cycloalkyl, —COO—(C1-C12)-alkyl, —COO—(C3-C12)-cycloalkyl, —CONH—(C1-C12)-alkyl, —CONH—(C3-C12)-cycloalkyl, —CO—(C1-C12)-alkyl, —CO—(C3-C12)-cycloalkyl, —N—[(C1-C12)-alkyl]2, —(C6-C20)-aryl, —(C6-C20)-aryl-(C1-C12)-alkyl, —(C6-C20)-aryl-O—(C1-C12)-alkyl, —(C3-C20)-heteroaryl, —(C3-C20)-heteroaryl-(C1-C12)-alkyl, —(C3-C20)-heteroaryl-O—(C1-C12)-alkyl, —COOH, —OH, —SO3H, —NH2, halogen.
Carbon chain shape selectivity by the mouse olfactory receptor OR-I7
Liu, Min Ting,Ho, Jianghai,Liu, Jason Karl,Purakait, Radhanath,Morzan, Uriel N.,Ahmed, Lucky,Batista, Victor S.,Matsunami, Hiroaki,Ryan, Kevin
supporting information, p. 2541 - 2548 (2018/04/12)
The rodent OR-I7 is an olfactory receptor exemplar activated by aliphatic aldehydes such as octanal. Normal alkanals shorter than heptanal bind OR-I7 without activating it and hence function as antagonists in vitro. We report a series of aldehydes designed to probe the structural requirements for aliphatic ligand chains too short to meet the minimum approximate 6.9 ? length requirement for receptor activation. Experiments using recombinant mouse OR-I7 expressed in heterologous cells show that in the context of short aldehyde antagonists, OR-I7 prefers binding aliphatic chains without branches, though a single methyl on carbon-3 is permitted. The receptor can accommodate a surprisingly large number of carbons (e.g. ten in adamantyl) as long as the carbons are part of a conformationally constrained ring system. A rhodopsin-based homology model of mouse OR-I7 docked with the new antagonists suggests that small alkyl branches on the alkyl chain sterically interfere with the hydrophobic residues lining the binding site, but branch carbons can be accommodated when tied back into a compact ring system like the adamantyl and bicyclo[2.2.2]octyl systems.
Exploiting the Biginelli reaction: Nitrogen-rich pyrimidine-based tercyclic α-helix mimetics
Lim, Zelong,Duggan, Peter J.,Wan, Soo San,Lessene, Guillaume,Meyer, Adam G.,Tuck, Kellie L.
, p. 1151 - 1160 (2016/02/16)
Several rationally designed pyrimidine-based scaffolds intended to mimic the spatial projection of the i, i+3, and i+7 residues of an α-helix and also possess improved aqueous solubility were prepared. A Biginelli-oxidation process was used to form the central pyrimidine ring of these scaffolds, which was subsequently manipulated to form pyrimidine-based tercyclic α-helix mimetics. A pyrimidine-based scaffold designed to mimic the α-helical BH3 domain of the pro-apoptotic Bak protein was also prepared as a putative inhibitor of the Bcl-xL/Bak protein-protein interaction. The pyrimidine-based tercyclic α-helix mimetics, and the putative Bcl-xL inhibitor, were assessed using a luminescence competition assay, however, none displayed inhibitory activity against Bcl-xL or Mcl-1.
An amphiphilic pillar[5]arene as efficient and substrate-selective phase-transfer catalyst
Ogoshi, Tomoki,Ueshima, Naosuke,Yamagishi, Tada-Aki
supporting information, p. 3742 - 3745 (2013/08/23)
An amphiphilic macrocyclic compound consisting of 10 tetra-alkyl phosphonium bromide groups and a pillar[5]arene core was prepared. This compound was soluble in both aqueous and organic media and acted as a highly efficient and substrate-selective phase-transfer catalyst. In particular, oxidation of the linear alkene1-hexene to 1-pentanal by KMnO4 was >99%, whereas that of the branched alkene 4-methyl-1-hexene was only 31%, under ideal conditions.
Steric effects and mechanism in the formation of hemi-acetals from aliphatic aldehydes
Daw, Graham,Regan, Andrew C.,Watt, C. Ian F.,Wood, Evan
, p. 1048 - 1057 (2014/01/06)
Some physical properties (pKa, log POW, boiling points) of hexanoic acid 1 (X = COOH) and its seven isomers 2, 3, 4, 5, 6, 7, 8 (X = COOH) are reported. Hexanal 1 (X = CHO) and its seven isomeric aldehydes 2, 3, 4, 5, 6, 7, 8 (X = CHO) are shown to equilibrate, in methanol solution, with their hemi-acetals. Logarithms of equilibrium constants correlate with values of Es for the isomeric C5H11 substituents, and with logs of relative rates for saponification of the corresponding methyl esters with ρ = 0.52, reflecting the reduced steric demand of hydrogen compared to oxygen in the quaternization of ester and aldehydic carbonyl groups. Rates of equilibration have also been measured in buffered methanol. For hexanal, with a 2:1 Et3N:AcOH buffer, the buffer-independent contribution is dominated by the methoxide catalysed pathway. Rates in this medium have been determined for isomers 1, 2, 3, 4, 5, 6, 7, 8 (X = CHO), and their logarithms do not correlate with logarithms of equilibrium constants for hemi-acetal formation or with substituent steric parameters derived from ester formation or saponification, indicating that the steric changes associated with full quaternization of the carbonyl group are not mirrored in the transition structures for hemi-acetal formation. It is suggested that transition states for hemi-acetal formation are relatively early so that steric interactions are effectively those between the nucleophile and ground state conformations of the aldehydes. A comparison of the entropies of hemi-acetal formation with entropies of activation has provided a basis for a suggested transition structure. Comparisons with acid chloride hydrolyses are made. Copyright 2013 John Wiley & Sons, Ltd. Logarithms of equilibrium constants for formation hemi-acetals of hexanal and its seven isomeric aldehydes correlate well with values of Es for the isomeric C5H11 substituents, and with logs of relative rates for saponification of the corresponding methyl esters. Logarithms of rate constants for hemi-acetal formation do not, indicating that the steric changes associated with full quaternization of the carbonyl group are not mirrored in the transition structures for hemi-acetal formation. The reasons for this are discussed. Copyright
Selective hydroformylation-hydrogenation tandem reaction of isoprene to 3-methylpentanal
Behr, Arno,Reyer, Sebastian,Tenhumberg, Nils
scheme or table, p. 11742 - 11747 (2012/01/04)
The hydroformylation of isoprene catalysed by rhodium phosphine complexes usually yields a broad mixture of the monoaldehydes, the isomeric methylpentenals, as well as the dialdehyde 3-methyl-1,6-hexandial. Under usual reaction conditions the products of a consecutive hydrogenation are only formed as minor by-products. Surprisingly we discovered now a selective auto-tandem reaction consisting of a hydroformylation and a hydrogenation step if a rhodium complex with the chelate ligand bis(diphenylphosphino)ethane is used as catalyst. If branched aromatic solvents like cumene are applied the conversion of isoprene is nearly quantitatively and the yield of the tandem product 3-methylpentanal amounts to 85%. The Royal Society of Chemistry 2011.
Toward the rhodium-catalyzed bis-hydroformylation of 1,3-butadiene to adipic aldehyde
Smith, Stuart E.,Rosendahl, Tobias,Hofmann, Peter
experimental part, p. 3643 - 3651 (2011/09/20)
The effects of the ligand to metal ratio, temperature, syngas pressure, partial pressures of H2 and CO, and new ligand structures have been examined on 12 of the most reasonable products resulting from the rhodium-catalyzed low-pressure hydroformylation of 1,3-butadiene. The selectivity for the desired linear dihydroformylation product, 1,6-hexanedial (adipic aldehyde), is essentially independent of all of these reaction parameters, except for ligand structure. However, the reaction parameters do have a substantial effect on the selectivity for the products, resulting from the branched addition of the rhodium hydride to the carbon-carbon double bond. The optimum reaction parameters and ligand have resulted in a so far unprecedented maximum selectivity of 50% for adipic aldehyde.
Discovery of novel thieno[2,3-d]pyrimidin-4-yl hydrazone-based cyclin-dependent kinase 4 inhibitors: synthesis, biological evaluation and structure-activity relationships
Horiuchi, Takao,Takeda, Yasuyuki,Haginoya, Noriyasu,Miyazaki, Masaki,Nagata, Motoko,Kitagawa, Mayumi,Akahane, Kouichi,Uoto, Kouichi
experimental part, p. 991 - 1002 (2011/10/02)
The design, synthesis, and evaluation of novel thieno[2,3-d]pyrimidin-4-yl hydrazone analogues as cyclin-dependent kinase 4 (CDK4) inhibitors are described. In continuing our program aim to search for potent CDK4 inhibitors, the introduction of a thiazole group at the hydrazone part has led to marked enhancement of chemical stability. Furthermore, by focusing on the optimization at the C-4′ position of the thiazole ring and the C-6 position of the thieno[2,3-d]pyrimidine moiety, compound 35 has been identified with efficacy in a xenograft model of HCT116 cells. In this paper, the potency, selectivity profile, and structure-activity relationships of our synthetic compounds are discussed.
Oxidation of alcohols by chlorine dioxide in organic solvents
Ganieva,Ganiev,Grabovskiy,Kabalnova
body text, p. 2328 - 2331 (2010/02/15)
The kinetics of oxidation of a series of alcohols (propan-2-ol, 2-methylpropan-1-ol, butan-1-ol, butan-2-ol, 3-methylpentan-1-ol, heptan-4-ol, decan-2-ol, cyclohexanol, borneol) by chlorine dioxide in organic solvents was studied using spectrophotometry. The reaction is described by the second-order rate equation w = k[ROH][ClO2]. The rate constants were measured in the range of 10-60 °C, and the activation parameters of the processes were calculated. The products were identified, and the yields were determined.
