372-18-9Relevant articles and documents
Protodeboronation of (Hetero)Arylboronic Esters: Direct versus Prehydrolytic Pathways and Self-/Auto-Catalysis
Assante, Michele,Geogheghan, Katherine J.,Hayes, Hannah L. D.,Jin, Na,Leach, Andrew G.,Lloyd-Jones, Guy C.,Noonan, Gary,Tomasi, Simone,Wei, Ran
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.
Continuous synthesis method of m-difluorobenzene based on micro-channel reactor
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Paragraph 0026-0063, (2021/04/10)
The invention discloses a continuous synthesis method of m-difluorobenzene based on a micro-reactor. The continuous synthesis method comprises the following steps: adding m-phenylenediamine and a hydrochloric acid solution into a first micro-channel reactor, and conducting reacting to obtain an m-phenylenediamine hydrochloride solution; subjecting the m-phenylenediamine hydrochloride solution to reacting with nitrogen trioxide in a second micro-channel reactor to prepare a dichlorom-phenylenediamine diazonium salt solution; subjecting the dichlorom-phenylenediamine diazonium salt to reacting with fluoboric acid in a tubular reactor, conducting quick centrifuging after the reaction is finished, washing precipitates obtained by centrifuging, and drying the precipitates to obtain m-phenylenediamine diazonium difluoroborate; and mixing the m-phenylenediamine diazonium difluoroborate with a solvent, adding the obtained mixture into a reactor, carrying out heating for decomposition, carrying out atmospheric distillation on a product in the reactor after the decomposition is finished, and collecting a fraction with a temperature of 82-84 DEG C. According to the invention, nitrogen trioxide is used as a diazotization agent, so the reaction is green, and no by-product is produced; and centrifugal mother liquor in the reaction process is concentrated and then recycled, so cost is saved, and reaction efficiency is high.
Gold Catalyzed Decarboxylative Cross-Coupling of Iodoarenes
Daley, Ryan A.,Morrenzin, Aaron S.,Neufeldt, Sharon R.,Topczewski, Joseph J.
supporting information, p. 13210 - 13218 (2020/09/01)
This report details a decarboxylative cross-coupling of (hetero)aryl carboxylates with iodoarenes in the presence of a gold catalyst (>25 examples, up to 96% yield). This reaction is site specific, which overcomes prior limitations associated with gold catalyzed oxidative coupling reactions. The reactivity of the (hetero)aryl carboxylate correlates qualitatively to the field effect parameter (Fortho). Reactions with isolated gold complexes and DFT calculations support a mechanism proceeding through oxidative addition at a gold(I) cation with decarboxylation being viable at either a gold(I) or a silver(I) species.