162101-25-9Relevant articles and documents
Protodeboronation of (Hetero)Arylboronic Esters: Direct versus Prehydrolytic Pathways and Self-/Auto-Catalysis
Hayes, Hannah L. D.,Wei, Ran,Assante, Michele,Geogheghan, Katherine J.,Jin, Na,Tomasi, Simone,Noonan, Gary,Leach, Andrew G.,Lloyd-Jones, Guy C.
supporting information, p. 14814 - 14826 (2021/09/13)
The kinetics and mechanism of the base-catalyzed hydrolysis (ArB(OR)2→ ArB(OH)2) and protodeboronation (ArB(OR)2→ ArH) of a series of boronic esters, encompassing eight different polyols and 10 polyfluoroaryl and heteroaryl moieties, have been investigated by in situ and stopped-flow NMR spectroscopy (19F,1H, and11B), pH-rate dependence, isotope entrainment,2H KIEs, and KS-DFT computations. The study reveals the phenomenological stability of boronic esters under basic aqueous-organic conditions to be highly nuanced. In contrast to common assumption, esterification does not necessarily impart greater stability compared to the corresponding boronic acid. Moreover, hydrolysis of the ester to the boronic acid can be a dominant component of the overall protodeboronation process, augmented by self-, auto-, and oxidative (phenolic) catalysis when the pH is close to the pKaof the boronic acid/ester.
1-cyclopropyl-4-oxo-7-fluoro-8-methoxy -1,4-dihydro-quinoline-3-carboxylic acid synthesizing method
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Paragraph 0023; 0066; 0067, (2017/01/26)
The invention discloses a synthesis method of 1-cyclopropyl-4-oxo-7-fluoro-8-methoxy-1,4-dihydroquinolyl-3-carboxylic acid. The synthesis method comprises the following reaction steps: reacting m-difluorophenyl with an organolithium reagent, reacting an obtained aryllithium intermediate with borate, quenching to obtain 2,6-difluorophenylboronic acid and 2,6-difluorophenylborate, reacting 2,6-difluorophenol obtained through oxidation with a methylating reagent, reacting the obtained 2,6-difluorophenylmethyl ether with the organolithium reagent, reacting the obtained corresponding aryllithium intermediate with carbon dioxide, reacting the obtained product with an acylchlorinating reagent to obtain 2,4-difluoro-3-methoxy benzoyl chloride, and performing cyclization, hydrolysis and the like to obtain the 1-cyclopropyl-4-oxo-7-fluoro-8-methoxy-1,4-dihydroquinolyl-3-carboxylic acid. The synthesis method has the advantages as follows: raw materials are easy to obtain; the yield in each step is high; the atom economy is high; the synthesis method is suitable for industrial application.
Polyfluoroorganoboron-oxygen compounds. 1: Polyfluorinated aryl(dihydroxy)boranes and tri(aryl)boroxins
Frohn,Adonin,Bardin,Starichenko
, p. 2827 - 2833 (2008/10/08)
A general preparative procedure for polyfluorinated aryl(dihydroxy)boranes C6H5-nFnB(OH)2 (n = 3 - 5) is described. Polyfluorinated aryl(dihydroxy)boranes are easily dehydrated to the corresponding tri(aryl)boroxins (C6H5-nFnBO)3 by thermal or chemical treatment. The property of the acids C6H5-nFnB(OH)2 to condensate depends on the number and on the position of the fluorine atoms in the aryl group. Examples of both classes of boron compounds were isolated as pure individuals and characterized by multinuclear NMR spectroscopy.