Cationic 1,2-Azaborine Adducts of Trimethylphosphine, Triphenylphosphine oxide, and Pyridine-N-oxide.
Ontology highlight
ABSTRACT:
SUBMITTER: Marwitz AJ
PROVIDER: S-EPMC3027061 | biostudies-literature | 2011 Jan
REPOSITORIES: biostudies-literature
Publications
Cationic 1,2-Azaborine Adducts of Trimethylphosphine, Triphenylphosphine oxide, and Pyridine-N-oxide.
Marwitz Adam J V AJ Jenkins Jesse T JT Zakharov Lev N LN Liu Shih-Yuan SY
Organometallics 20110101 1
The first cationic 1,2-azaborine adducts of neutral phosphorous- and oxygen-based nucleophiles have been synthesized and characterized via spectroscopic and single crystal X-ray diffraction analysis. ...[more]
Similar Datasets
Project description:The BN analogue of ortho-benzyne, 1,2-azaborine, is shown to bind carbon monoxide and a xenon atom under matrix isolation conditions, demonstrating its strongly Lewis acidic superelectrophilic nature. The Lewis acid-base complexes involving CO and Xe can be cleaved photochemically and reformed by mildly annealing the matrices. The interaction energy of 1,2-azaborine with Xe is 3 kcal mol-1 according to quantum chemical computations, and is similar to that of the superelectrophilic carbene difluorovinylidene.
| S-EPMC6609157 | biostudies-literature
Project description:We provide a seminal example of the utility of the 1,2-azaborine motif as a 4C+1N+1B synthon in organic synthesis. Specifically, conditions for the practically scalable photoisomerization of 1,2-azaborine in a flow reactor are reported that furnish aminoborylated cyclobutane derivatives. The C-B bonds could also be functionalized to furnish a diverse set of highly substituted cyclobutanes.
| S-EPMC6917847 | biostudies-literature
Project description:The tile compound, C(12)H(12)N(2)O(2)S(2), lies on an inversion center. The two pyridyl rings are parallel to each other. The structure is devoid of any classical hydrogen bonds due to lack of appropriate donors and acceptors for such bonds. However, non-classical hydrogen bonds of the types C-H?O and C-H?S stabilize the structure.
| S-EPMC2972030 | biostudies-literature
Project description:The BN analogue of ortho-benzyne, 1,2-azaborine, is generated by flash vacuum pyrolysis, trapped under cryogenic conditions, and studied by direct spectroscopic techniques. The parent BN aryne spontaneously binds N2 and CO2, thus demonstrating its highly reactive nature. The interaction with N2 is photochemically reversible. The CO2 adduct of 1,2-azaborine is a cyclic carbamate which undergoes photocleavage, thus resulting in overall CO2 splitting.
| S-EPMC4564995 | biostudies-literature
Project description:A mild, catalytic, atom economical synthesis of imidazo[1,2-a]pyridines has been developed: catalytic PicAuCl2 in the presence of an acid produces a range imidazo[1,2-a]pyridines in good yield. This strategy is mild and forseen to be of particular use for the installation of stereogenic centers adjacent to the imidazo[1,2-a]pyridine ring without loss of enantiomeric excess.
| S-EPMC4019451 | biostudies-literature
Project description:1,2-dihydro-1,2-azaborine is a structural and electronic analogue of benzene which is able to occupy benzene-binding pockets in T4 lysozyme and has been proposed as suitable arene-mimicking group for biological and pharmaceutical applications. Its applicability in a biological context requires it to be able to resist modification by xenobiotic-degrading enzymes like the P450 cytochromes. Quantum chemical computations described in this work show that 1,2-dihydro-1,2-azaborine is much more prone to modification by these enzymes than benzene, unless steric crowding of the ring prevents it from reaching the active site, or otherwise only allows reaction at the less reactive C4-position. This novel heterocyclic compound is therefore expected to be of limited usefulness as an aryl bioisostere.
| S-EPMC4974919 | biostudies-literature
Project description:In this study, the researchers isolated a colorless waxy solid from the chloroform extract of Allium stipitatum as Compound 1. They demonstrated compound 1 is a potent bactericidal agent against nonreplicating Mycobacterium tuberculosis. Using microarray technology the authors report gene expression profiles in cells treated with either 2, 5, or 10 ug/ml of compound 1 or an equivalent amount of DMSO as control for 6 h. Gene expression studies revealed that transcriptional profiles elicited in response to compound 1 were similar to the profiles generated during treatment of cells with compounds such as menadione and 8-quinolinol that result in oxidative stress. They included the thioredoxin system components encoded by trxB2 and trxC as well as several genes associated with the heat shock response such as clpB, sigH, dnaJ, dnaK, hsp, Rv0331, Rv3463, Rv3054c, and Rv1334-Rv1335. These results suggest that compound 1 possibly generates damaged proteins and other oxidative stress signals as part of its mechanism of action. The following is the full abstract of this published study. O'Donnell G, et al. (2009) J Nat Prod 72(3):360-365 From Allium stipitatum, three pyridine-N-oxide alkaloids (1-3) possessing disulfide functional groups were isolated. The structures of these natural products were elucidated by spectroscopic means as 2-(methyldithio)pyridine-N-oxide (1), 2-[(methylthiomethyl)dithio]pyridine-N-oxide (2), and 2,2'-dithio-bis-pyridine-N-oxide (3). The proposed structure of 1 was confirmed by synthetic S-methylthiolation of commercial 2-thiopyridine-N-oxide. Compounds 1 and 2 are new natural products, and 3 is reported for the first time from an Allium species. All compounds were evaluated for activity against fast-growing species of Mycobacterium, methicillin-resistant Staphylococcus aureus, and a multidrug-resistant (MDR) variants of S. aureus. Compounds 1 and 2 exhibited minimum inhibitory concentrations (MICs) of 0.5-8 mug/ml against these strains. A small series of analogues of 1 were synthesized in an attempt to optimize antibacterial activity, although the natural product had the most potent in vitro activity. In a whole-cell assay at 30 mug/ml, 1 was shown to give complete inhibition of the incorporation of (14)C-labeled acetate into soluble fatty acids, indicating that it is potentially an inhibitor of fatty acid biosynthesis. In a human cancer cell line antiproliferative assay, 1 and 2 displayed IC(50) values ranging from 0.3 to 1.8 muM with a selectivity index of 2.3 when compared to a human somatic cell line. Compound 1 was evaluated in a microarray analysis that indicated a similar mode of action to menadione and 8-quinolinol by interfering with the thioredoxin system and up-regulating the production of various heat shock proteins. This compound was also assessed in a mouse model for in vivo toxicity. A dose response design type examines the relationship between the size of the administered dose and the extent of the response of the organism(s). Compound Based Treatment: Allium stipitatum (garlic) extract
2009-08-15 | GSE17640 | GEO
Project description:In this study, the researchers isolated a colorless waxy solid from the chloroform extract of Allium stipitatum as Compound 1. They demonstrated compound 1 is a potent bactericidal agent against nonreplicating Mycobacterium tuberculosis. Using microarray technology the authors report gene expression profiles in cells treated with either 2, 5, or 10 ug/ml of compound 1 or an equivalent amount of DMSO as control for 6 h. Gene expression studies revealed that transcriptional profiles elicited in response to compound 1 were similar to the profiles generated during treatment of cells with compounds such as menadione and 8-quinolinol that result in oxidative stress. They included the thioredoxin system components encoded by trxB2 and trxC as well as several genes associated with the heat shock response such as clpB, sigH, dnaJ, dnaK, hsp, Rv0331, Rv3463, Rv3054c, and Rv1334-Rv1335. These results suggest that compound 1 possibly generates damaged proteins and other oxidative stress signals as part of its mechanism of action. The following is the full abstract of this published study. O'Donnell G, et al. (2009) J Nat Prod 72(3):360-365 From Allium stipitatum, three pyridine-N-oxide alkaloids (1-3) possessing disulfide functional groups were isolated. The structures of these natural products were elucidated by spectroscopic means as 2-(methyldithio)pyridine-N-oxide (1), 2-[(methylthiomethyl)dithio]pyridine-N-oxide (2), and 2,2'-dithio-bis-pyridine-N-oxide (3). The proposed structure of 1 was confirmed by synthetic S-methylthiolation of commercial 2-thiopyridine-N-oxide. Compounds 1 and 2 are new natural products, and 3 is reported for the first time from an Allium species. All compounds were evaluated for activity against fast-growing species of Mycobacterium, methicillin-resistant Staphylococcus aureus, and a multidrug-resistant (MDR) variants of S. aureus. Compounds 1 and 2 exhibited minimum inhibitory concentrations (MICs) of 0.5-8 mug/ml against these strains. A small series of analogues of 1 were synthesized in an attempt to optimize antibacterial activity, although the natural product had the most potent in vitro activity. In a whole-cell assay at 30 mug/ml, 1 was shown to give complete inhibition of the incorporation of (14)C-labeled acetate into soluble fatty acids, indicating that it is potentially an inhibitor of fatty acid biosynthesis. In a human cancer cell line antiproliferative assay, 1 and 2 displayed IC(50) values ranging from 0.3 to 1.8 muM with a selectivity index of 2.3 when compared to a human somatic cell line. Compound 1 was evaluated in a microarray analysis that indicated a similar mode of action to menadione and 8-quinolinol by interfering with the thioredoxin system and up-regulating the production of various heat shock proteins. This compound was also assessed in a mouse model for in vivo toxicity. A dose response design type examines the relationship between the size of the administered dose and the extent of the response of the organism(s). Compound Based Treatment: Allium stipitatum (garlic) extract dose_response_design
2009-08-15 | E-GEOD-17640 | biostudies-arrayexpress
Project description:Here, a large-scale feasible, chromatography-free process to purge triphenylphosphine oxide (TPPO) from the crude product of Mitsunobu and Wittig reactions has been developed. Divergence in physicochemical properties like polarity and solubility of TPPO against the product was utilized to precipitate TPPO directly from the reaction mixture and eliminate by simple filtration on a kilogram scale at a pilot plant with high purity of the product.
| S-EPMC8173612 | biostudies-literature