- Protodeboronation of (Hetero)Arylboronic Esters: Direct versus Prehydrolytic Pathways and Self-/Auto-Catalysis
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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.
- Hayes, Hannah L. D.,Wei, Ran,Assante, Michele,Geogheghan, Katherine J.,Jin, Na,Tomasi, Simone,Noonan, Gary,Leach, Andrew G.,Lloyd-Jones, Guy C.
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supporting information
p. 14814 - 14826
(2021/09/13)
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- Development of a Concise Multikilogram Synthesis of LPA-1 Antagonist BMS-986020 via a Tandem Borylation-Suzuki Procedure
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The process development for the synthesis of BMS-986020 (1) via a palladium catalyzed tandem borylation/Suzuki reaction is described. Evaluation of conditions culminated in an efficient borylation procedure using tetrahydroxydiboron followed by a tandem Suzuki reaction employing the same commercially available palladium catalyst for both steps. This methodology addressed shortcomings of early synthetic routes and was ultimately used for the multikilogram scale synthesis of the active pharmaceutical ingredient 1. Further evaluation of the borylation reaction showed useful reactivity with a range of substituted aryl bromides and iodides as coupling partners. These findings represent a practical, efficient, mild, and scalable method for borylation.
- Smith, Michael J.,Lawler, Michael J.,Kopp, Nathaniel,McLeod, Douglas D.,Davulcu, Akin H.,Lin, Dong,Katipally, Kishta,Sfouggatakis, Chris
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p. 1859 - 1863
(2017/11/24)
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- Flow Chemistry on Multigram Scale: Continuous Synthesis of Boronic Acids within 1 s
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The benefits and limitations of a simple continuous flow setup for handling and performing of organolithium chemistry on the multigram scale is described. The developed metalation platform embodies a valuable complement to existing methodologies, as it combines the benefits of Flash Chemistry (chemical synthesis on a time scale of 1 s) with remarkable throughput (g/min) while mitigating the risk of blockages.
- Hafner, Andreas,Meisenbach, Mark,Sedelmeier, Joerg
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supporting information
p. 3630 - 3633
(2016/08/16)
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- Fast and Tight Boronate Formation for Click Bioorthogonal Conjugation
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A new click bioorthogonal reaction system was devised to enable the fast ligation (kON≈340 m-1 s-1) of conjugatable derivatives of a rigid cyclic diol (nopoldiol) and a carefully optimized boronic acid partner, 2-methyl-5-carboxymethylphenylboronic acid. Using NMR and fluorescence spectroscopy studies, the corresponding boronates were found to form reversibly within minutes at low micromolar concentration in water, providing submicromolar equilibrium constant (Keq≈105-106 m-1). Efficient protein conjugation under physiological conditions was demonstrated with model proteins thioredoxin and albumin, and characterized by mass spectrometry and gel electrophoresis.
- Akgun, Burcin,Hall, Dennis G.
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supporting information
p. 3909 - 3913
(2016/03/19)
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- Preparation method of benzochromene derivative
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The invention discloses a preparation method of a benzochromene derivative shown as a formula (I). The benzochromene derivative can be taken as a synthesis intermediate of a drug such as a synthesis intermediate of Velpatasvir. Cheap and available 2-fluoro halogenated benzene is taken as a starting material, a brand-new synthetic route for preparing the benzochromene derivative is provided, the total yield of the whole reaction route is high, and the method is suitable for large-scale industrial production.
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Paragraph 0093; 0094; 0095
(2016/10/31)
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- Transition-metal-free synthesis of phenanthridinones from biaryl-2-oxamic acid under radical conditions
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Na2S2O8-promoted decarboxylative cyclization of biaryl-2-oxamic acid for phenanthridinones has been developed. This work illustrates the first example of intramolecular decarboxylative amidation of unactivated arene under transition-metal-free conditions. Additionally, this approach provides an efficient and economical method to access biologically interesting phenanthridinones, an important structure motif in many natural products. (Chemical Equation Presented).
- Yuan, Ming,Chen, Li,Wang, Junwei,Chen, Shenjie,Wang, Kongchao,Xue, Yongbo,Yao, Guangmin,Luo, Zengwei,Zhang, Yonghui
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supporting information
p. 346 - 349
(2015/02/19)
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- An easy route to (hetero)arylboronic acids
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An unprecedented spontaneous reactivity between diazonium salts and diboronic acid has been unveiled, leading to a versatile arylboronic acid synthesis directly from (hetero)arylamines. This fast reaction (35 min overall) tolerates a wide range of functional groups and is carried out under very mild conditions. The radical nature of the reaction mechanism has been investigated.
- Erb, William,Hellal, Akila,Albini, Mathieu,Rouden, Jacques,Blanchet, Jerome
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supporting information
p. 6608 - 6612
(2014/06/09)
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- Sequential one-pot access to molecular diversity through aniline aqueous borylation
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On the basis of our recently reported aniline aqueous borylation, molecular diversity was achieved in a one-pot process by combining other reactions such as esterification, Suzuki-Miyaura coupling, hydrogenolysis, or Petasis borono-Mannich.
- Erb, William,Albini, Mathieu,Rouden, Jacques,Blanchet, Jrme
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p. 10568 - 10580
(2015/01/08)
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- Nickel-catalyzed borylation of halides and pseudohalides with tetrahydroxydiboron [B2(OH)4]
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Arylboronic acids are gaining increased importance as reagents and target structures in a variety of useful applications. Recently, the palladium-catalyzed synthesis of arylboronic acids employing the atom-economical tetrahydroxydiboron (BBA) reagent has been reported. The high cost associated with palladium, combined with several limitations of both palladium- and copper-catalyzed processes, prompted us to develop an alternative method. Thus, the nickel-catalyzed borylation of aryl and heteroaryl halides and pseudohalides using tetrahydroxydiboron (BBA) has been formulated. The reaction proved to be widely functional group tolerant and applicable to a number of heterocyclic systems. To the best of our knowledge, the examples presented here represent the only effective Ni-catalyzed Miyaura borylations conducted at room temperature.
- Molander, Gary A.,Cavalcanti, Livia N.,Garcia-Garcia, Carolina
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p. 6427 - 6439
(2013/07/26)
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- POLYCYCLIC RING-FUSED COMPOUND AND ORGANIC THIN FILM TRANSISTOR UTILIZING SAME
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A compound for an organic thin film transistor represented by the following formula (1):
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Page/Page column 24
(2012/11/08)
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- Substituent effects on aryltrifluoroborate solvolysis in water: Implications for Suzuki-Miyaura coupling and the design of stable 18F-labeled aryltrifluoroborates for use in PET imaging
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(Chemical Equation Presented) Whereas electron withdrawing substituents retard the rate of aryltrifluoroborate solvolysis, electron-donating groups enhance it. Herein is presented a Hammett analysis of the solvolytic lability of aryltrifluoroborates where log(Ksolv) values correlate to a values with a ρ value of approximately -1. This work provides a predictable rubric for tuning the reactivity of boron for several uses including 18F-labeled PET reagents and has mechanistic implications for ArBF3-enhanced ligandless metal-mediated cross coupling reactions with aryltrifluoroborates.
- Ting, Richard,Harwig, Curtis W.,Lo, Justin,Li, Ying,Adam, Michael J.,Ruth, Thomas J.,Petrin, David M.
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p. 4662 - 4670
(2008/09/20)
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- Thiazolyl amide derivatives
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The present invention relates to novel compounds, to a process for their preparation and to their use as medicaments, in particular as antiviral medicaments.
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- Sulfonamide derivatives
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The present invention provides certain sulfonamide derivatives useful for potentiating glutamate receptor function in a mammal and therefore, useful for treating a wide variety of conditions, such as psychiatric and neurological disorders.
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- Sulphonamide derivatives
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Glutamate receptor function in a mammal may be potentiated using an effective amount of a compound of formulaR1—L—NHSO2R2??Iin whichR1 represents an unsubstituted or substituted aromatic or heteroaromatic group;R2 represents (1-6C)alkyl, (3-6C)cycloalkyl, (1-6C)fluoroalkyl, (1-6C)chloroalkyl, (2-6C)alkenyl, (1-4C)alkoxy(1-4C)alkyl, phenyl which is unsubstituted or substituted by halogen, (1-4C)alkyl or (1-4C)alkoxy, or a group, of formula R3R4N in which R3 and R4 each independently represents (1-4C)alkyl or, together with the nitrogen atom to which they are attached form an azetidinyl, pyrrolidinyl, piperidinyl, morpholino, piperazinyl, hexahydroazepinyl or octahydroazocinyl group; andL represents a (2-4C)alkylene chain which is unsubstituted or substituted by one or two substituents selected independently from (1-6C)alkyl, aryl(1-6C)alkyl, (2-6C)alkenyl, aryl(2-6C)alkenyl and aryl, or by two substituents which, together with the carbon atom or carbon atoms to which they are attached form a (3-8C)carbocyclic ring;and pharmaceutically acceptable salts thereof.Also disclosed are compounds of formula I, processes for preparing them and pharmaceutical compositions containing them.
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- (Fluoroorgano)fluoroboranes and -fluoroborates I: Synthesis and spectroscopic characterization of potassium fluoroaryltrifluoroborates and fluoroaryldifluoroboranes
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A convenient preparation of K[ArBF3] (Ar=2-C6H4F, 3-C6H4F, 4-C6H4F, 2,6-C6H3F2, 3,5-C6H3F2, 2,4,6-C6H2F3, 3,4,5-C6H2F3, 2,3,4,5-C6HF4 and C6F5) is offered and the IR and multinuclear NMR spectra of these salts are reported. Treatment of the trifluoroborate salts with BF3 in chlorocarbon solvents provides an easy synthetic route to the corresponding aryldifluoroboranes ArBF2. The multinuclear NMR spectra of ArBF2 are presented. The electron substituent effect of the [-BF3]--group shows this substituent as one of the strongest σ-electron donors, while its π-electron influence is negligible (σI=-0.32, σR=-0.07).
- Frohn,Franke,Fritzen,Bardin
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p. 127 - 135
(2007/10/03)
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- Reaction of 4-ethoxycarbonyl-2-phenyl-4,5-dihydrooxazol-5-one with organolead(IV) triacetates. A route to some α-arylglycine and α-vinylglycine derivatives
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4-Ethoxycarbonyl-2-phenyl-4,5-dihydrooxazol-5-one undergoes rapid arylation and vinylation with arylead triacetates and (E)-styryllead triacetates, respectively. The resulting moisture-sensitive 4-aryl- and 4-styryl-oxazolones undergo hydrolysis and decar
- Koen, Mark J.,Morgan, Jacqueline,Pinhey, John T.,Sherry, Christopher J.
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p. 487 - 491
(2007/10/03)
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