2370-12-9Relevant academic research and scientific papers
MACROCYCLIC BROAD SPECTRUM ANTIBIOTICS
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Paragraph 00681, (2017/08/01)
Provided herein are antibacterial compounds, wherein the compounds in some embodiments have broad spectrum bioactivity. In various embodiments, the compounds act by inhibition of bacterial type 1 signal peptidase (SpsB), an essential protein in bacteria. Pharmaceutical compositions and methods for treatment using the compounds described herein are also provided.
Etheric C-O bond hydrogenolysis using a tandem lanthanide triflate/supported palladium nanoparticle catalyst system
Atesin, Abdurrahman C.,Ray, Natalie A.,Stair, Peter C.,Marks, Tobin J.
supporting information, p. 14682 - 14685 (2012/11/13)
Selective hydrogenolysis of cyclic and linear ether C-O bonds is accomplished by a tandem catalytic system consisting of lanthanide triflates and sinter-resistant supported palladium nanoparticles in an ionic liquid. The lanthanide triflates catalyze endothermic dehydroalkoxylation, while the palladium nanoparticles hydrogenate the resulting intermediate alkenols to afford saturated alkanols with high overall selectivity. The catalytic C-O hydrogenolysis is shown to have significant scope, and the C-O bond cleavage is turnover-limiting.
Conformational Analysis and Stereodynamics of Primary Acyclic Alkyl Radicals by EPR Spectroscopy
Ingold, K. U.,Nonhebel, D. C.,Walton, J. C.
, p. 2859 - 2869 (2007/10/02)
The EPR spectra of n-alkyl, 2-methylalkyl, 2,2-dimethylalkyl, 2,2,3-trimethylbutyl, and 2,2,3,3-tetramethylbutyl radicals indicate that at 90 K they exist in "rigid" conformations with respect to rotation about the Cβ-Cγ bonds.The preferred conformations about the Cα-Cβ and Cβ-Cγ bonds were deduced by analysis of the β- and γ-H hyperfine splittings (hfs). 2,2,3,3-Tetramethylbutyl radicals, the only radicals with a CH3 group approximately all-trans with respect to the semioccupied p-orbital, were also the only radicals to show resolved δ-hfs.The barriers to internal rotation of the methyl groups in n-propyl, isobutyl, neopentyl, 2,2-bis(trideuteriomethyl)butyl, and 2,2,3,3-tetramethylbutyl radicals were obtained by line shape analysis; the ethyl rotation barrier in 2,2-bis(trideuteriomethyl)butyl and the tert-butyl rotation barrier in 2,2,3,3-tetramethylbutyl radicals were estimated in a similar way.The experimental hfs of trans γ-hydrogens were shown to fit a relationship of the form aHγ = 0.1 +7.9 cos2 Φ, where Φ is the dihedral angle between the SOMO and the plane through Cα, Cβ, and Cγ.Trends in the internal rotation barriers of the alkyl groups were adequately accounted for in terms of steric effects.
Cyclometallation of Dialkylbis(triethylphosphine)platinum(II) Complexes: Formation of Pt,Pt-Bis(triethylphosphine)platinacycloalkanes
DiCosimo, Robert,Moore, Stephen S.,Sowinski, Allan F.,Whitesides, George M.
, p. 124 - 133 (2007/10/02)
The thermal decompositions of three analogues of bis(triethylphosphine)dineopentylplatinum(II) (L2Pt2 (1)) - L2Pt2 (3), L2Pt2 (5), and L2Pt2 (7) - have been examined.Compounds 3 and 7 decompose more rapidly than 1 by a factor of ca. 104 to give as products Pt,Pt-bis(triethylphosphine)-3,3-dimethylplatinacyclohexane (4) and Pt,Pt-bis(triethylphosphine)-3,3,5,5-tetramethylplatinacyclohexane (8), respectively, and 1 equiv of the corresponding alkane.Compound 5 decomposes at a rate ca. 50 times faster than 1 to yield Pt,Pt-bis(triethylphosphine)-2,4,4-trimethylplatinacyclopentane (6a), -3-methyl-3-n-propylplatinacyclobutane (6b), and -3,3-dimethylplatinacyclohexane (6c).The conversion of 3 to 4 and 5 to 6a proceeds by dissociation of triethylphosphine, intramolecular oxidative addition of a δ carbon-hydrogen bond of the alkyl groups to platinum, and reductive elimination of alkane.The decomposition of L2Pt2 (11) proceeds by β-hydride elimination rather than cleavage of a carbon-hydrogen bond and formation of platinacycloalkane.The difference in the free energies of activation for reactions which form four- and five-membered platinacycloalkanes is small (ΔΔG(excit.) ca./= 4 kcal mol-1); that for reactions wich form four- and six-membered rings is smaller (ΔΔG(excit.) ca./= 0 kcal mol-1).We identify these values of ΔΔG(excit.) with estimates of the strain energies of these rings, assuming the strain energy of the platinacyclohexane is small.The important conclusion from these studies is that the strain energy of the platinacyclobutane studied here is small (-1).
Preparation of 15-deoxy-16-hydroxyprostaglandins
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, (2008/06/13)
Analogues of PGE1 having the structural formula, STR1 in which J is R-hydroxymethylene or S-hydroxymethylene; R1 is hydrogen; R2 is hydrogen or together with R4 is a methylene chain of 2 to 3 carbon atoms such that a cycloalkyl of 5 to 6 carbon atoms inclusive is formed; R3 is hydrogen or methyl, or together with R4 is a methylene or a lower alkylated methylene chain of 2 to 5 carbon atoms such that a cycloalkyl or a lower alkylated cycloalkyl of 4 to 7 carbon atoms inclusive is formed, or together with R4 is bicycloalkyl or bicycloalkenyl moiety having the formula: STR2 SUCH THAT A BICYCLOALKYL OR BICYCLOALKENYL COMPOUND IS FORMED, WHEREIN M AND N ARE INTEGERS HAVING A VALUE FROM 0 TO 3, P IS AN INTEGER HAVING A VALUE FROM 0 TO 4 AND Q IS AN INTEGER HAVING A VALUE OF FROM 1 TO 4 AND WHEREIN THE DOUBLE BOND OF SUCH BICYCLOALKENYL IS IN THE M, N, P, OR Q BRIDGE; R4 is hydrogen or methyl or together with R2 or R3 forms a cycloalkyl or bicycloalkyl or bicycloalkenyl as defined above, or together with R5 is a methylene chain of 3 to 5 carbon atoms such that a cycloalkyl of 4 to 6 carbon atoms inclusive is formed; R5 is selected from the group consisting of hydrogen, straight-chain alkyl having from 1 to 3 carbon atoms or together with R4 forms a cycloalkyl as defined above; and R6 is hydrogen or straight-chain alkyl having from 1 to 3 carbon atoms are disclosed. Pge1 ester analogues of the above formula, limited to the structures wherein two of R2, R3 R4 and R5 form a cycloalkyl, lower alkylated cycloalkyl, bicycloalkyl or bicycloalkenyl are also disclosed. The prostaglandin analogues selectively produce bronchodilation and decrease gastric secretion in vivo. Methods of preparing the analogues and starting materials required in the synthesis of the analogues are also disclosed.
Novel 16 hydroxy 15-deoxy-5-cis-prostenoic acids and esters
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, (2008/06/13)
This disclosure describes certain hydroxy substituted 15-deoxy-5-cis-prostenoic acids and esters useful as hypotensive agents, anti-ulcer agents, bronchodilators, anti-microbial agents, anticonvulsants, or as intermediates.
