24480-99-7Relevant academic research and scientific papers
TRNA SYNTHETASE INHIBITORS
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Paragraph 00452; 00454-00455, (2019/07/30)
Disclosed herein are secondary amine compounds that inhibit tRNA synthetase. The compounds of the invention are useful in inhibiting tRNA synthetase in Gram-negative bacteria and are useful in killing Gram-negative bacteria. The secondary amine compounds of the invention are also useful in the treatment of tuberculosis.
Regioselective epoxidation of different types of double bonds over large-pore titanium silicate Ti-β
Sasidharan, Manickam,Bhaumik, Asim
experimental part, p. 60 - 67 (2010/12/18)
Regioselective epoxidation of different types of double bonds located within the cyclic and acyclic parts of bulky olefins has been investigated using large-pore titanium silicate Ti-β in the presence of dilute aqueous H 2O2 as oxidant under mild liquid-phase conditions. Our experimental results revealed that side-chain vinylic double bonds are selectively epoxidized than those in the cyclohexene-ring. The epoxidation tendency of various bulky olefins with different positional and/or geometric isomers over Ti-β follows the order: terminal -CC- > ring -CC- ≈ bicyclic ring -CC- > allylic C - H bond. Unlike 4-vinyl-1-cyclohexene, epoxidation of an equimolar mixture of cyclohexene and 1-hexene under identical conditions using Ti-β exhibits completely different selectivity and product distributions. Steric factor and accessibility of reactants to active Ti-sites are responsible for the observed regioselectivity of bulky alkenes.
Free-radical based cycloalkanol synthesis and annulation from thioacetal precursors
Yadav, Veejendra,Fallis, Alex G.
, p. 779 - 789 (2007/10/02)
A general procedure for the synthesis of diverse cyclopentanols via free-radical cyclization of unsaturated 1,3-oxathiolanes and 1,3-oxathiolan-5-ones is described.The scope of these reactions, including preliminary rate studies that indicate that the 1,3-oxathiolan-5-ones cyclize at a useful rate (1.4*106 M-1s-1 at 80 deg C), has been examined.This permits the rapid assembly, by intramolecular annulation, of various additional ring systems, including bicyclooctanols, bicyclononanols, and bicyclooctanols for use in total synthesis. Key words: radical cyclization, oxathiolanes, oxathiolanones.
ORGANOBORANES FOR SYNTHESIS. 4. OXIDATION OF ORGANOBORANES WITH PYRIDINIUM CHLOROCHROMATE. A DIRECT SYNTHESIS OF ALDEHYDES FROM TERMINAL ALKENES VIA HYDROBORATION
Brown, Herbert C.,Kulkarni, Surendra U.,Rao, C. Gundu,Patil, Vemanna D.
, p. 5515 - 5522 (2007/10/02)
The oxidation of trialkylboranes containing primary alkyl groups with pyridinium chlorochromate (PCC) in methylene chloride provides the corresponding aldehydes in good yields.The stoichiometry for the oxidation of alcohols, borate esters and trialkylboranes with PCC has been examined.In view of the poor regioselectivity (only 94percent primary alkyl groups) and functional group tolerance observed in the hydroboration with borane (BH3*THF or BH3*SMe2), a more selective hydroborating agent, bis(3-methyl-2-butyl)borane (disiamylborane), was utilized for the preparation of aldehydes from terminal alkenes.However, the formation of 3-methyl-2-butanone as a by-product, and the requirement of six moles of PCC per mole of aldehyde are major disadvantages in this method.This difficulty was circumvented by employing monochloroborane-dimethyl sulfide for hydroboration.This reagent exhibits high regioselectivity (> 99percent primary alkyl groups) in the hydroboration of terminal alkenes.Oxidation of the resulting dialkylchloroborane following hydrolysis affords the desired aldehydes in satisfactory yields.Consequently, the hydroboration of terminal alkenes, followed by PCC oxidation, represents a direct convenient method for the transformation of alkenes into the corresponding aldehydes.
INTRAMOLECULAR N-ALKENYLNITRONE-ADDITIONS. REGIO- AND STEREOCHEMISTRY
Oppolzer, W.,Siles, S.,Snowden, R. L.,Bakker, B. H.,Petrzilka, M.
, p. 3497 - 3509 (2007/10/02)
Efficient intramolecular cycloadditions of N-3-alkenyl- and N-4-alkenylnitrones proceed with opposite regioselection which is modified by dipolarophile-substituent effects.Polycyclic isoxazolidines are obtained in a highly stereocontrolled fashion, consistent with an endo-addition of the Z-nitrones.
