3262-89-3Relevant articles and documents
Synthesis of B,O,N-Doped Adamantanes and Diamantanes by Condensation of Oximes with Boronic Acids
Golovanov, Ivan S.,Sukhorukov, Alexey Yu.,Nelyubina, Yulia V.,Khomutova, Yulia A.,Ioffe, Sema L.,Tartakovsky, Vladimir A.
, p. 6728 - 6736 (2015)
Condensation of oximes with boronic acids RB(OH)2 or B(OH)3 affords remarkably stable 2,4,10-trioxa-1,5,7-triaza-3-boroadamantanes via an unprecedented multicomponent process. The mechanism involves the reversible generation of unstable oxime cyclotrimers, which are readily intercepted by boronic acids.
Ring expansion reactions of pentaphenylborole with dipolar molecules as a route to seven-membered boron heterocycles
Huang, Kexuan,Martin, Caleb D.
, p. 1869 - 1875 (2015)
Reactions of pentaphenylborole with isocyanates, benzophenone, and benzaldehyde produced new seven-membered heterocycles in high yields. For 1-adamantyl isocyanate, a BNC5 heterocycle was obtained from the insertion of the C-N moiety into the five-membered borole, whereas for 4-methoxyphenyl isocyanate, a BOC5 heterocycle was generated from the insertion of the C-O unit. These reactions are believed to occur via a mechanism wherein coordination of the nucleophile to the borole (1-adamantyl, N-coordination or O-coordination for 4-methoxyphenyl) is followed by ring expansion to afford the observed seven-membered heterocycles. The selectivity to form B-O- or B-N-containing heterocycles is based on the polarization of the isocyanate implying tunable reactivity for the system. Having observed that isocyanates react as 1,2-dipoles with pentaphenylborole, we examined benzophenone and benzaldehyde, which both reacted to insert C-O units into the ring. This represents a new efficient method for preparing rare seven-membered boracycles.
Solubility of Phenylboronic Acid and its Cyclic Esters in Organic Solvents
Leszczyński, Pawe?,Hofman, Tadeusz,Sporzyński, Andrzej
, p. 814 - 824 (2020)
The solubilities of phenylboronic acid, its pinacol ester and azaester in organic solvents (chloroform, 3-pentanone, acetone, dipropyl ether and methylcyclohexane) have been determined experimentally by a dynamic method, in which the disappearance of turbidity was determined by measuring of light intensity using a luminance probe. Phenylboronic acid has high solubility in ether and ketones, moderate in chloroform and very low in hydrocarbon. Pinacol ester and azaester show better solubility than the parent acid in all tested solvents. For pinacol ester differences between particular solvents are small, while for azaester the differences are significant. For both esters the highest solubility is observed in chloroform and the lowest in the hydrocarbon. The results have been correlated by the Wilson, NRTL and Redlich–Kister equations. For the phenylboronic acid better correlation of the data is obtained by polynomials in comparison with the above equations. It is connected with additional acid-anhydride equilibrium in the system. The influence of polarity of the solvents on the solubility is discussed.
Can triorganoboroxins exist in a "monomeric" R-B=O form? MNDO calculations and ebulliometric molecular weight determination
Sporzynski, Andrzej,Szatylowicz, Halina
, p. 31 - 34 (1994)
MNDO calculations were made for triethylboroxin (EtBO)3 and triphenylboroxin (PhBO)3 using both X-ray determined and optimized geometry of these molecules.The results were compared with hypothetical "monomeric" molecules R-B-O.Calculated energies of trimerization are about -200 kJ mol-1 for both compounds and confirm the much higher stability of the "trimer".Ebulliometric determination of molecular weight of triphenylboroxin in 2-pentanone confirms its trimeric character. Key words: Boroxin; MNDO calculations
Bimetallic zirconium heterocycles supported by boron-oxygen ligands
Balkwill, Jessica E.,Cole, Sarah C.,Coles, Martyn P.,Hitchcock, Peter B.
, p. 3548 - 3552 (2002)
Reaction between bis(cyclopentadienyl)dimethylzirconium, ZrCp2(CH3)2, and phenylboronic anhydride, (PhBO)3, resulted in the formation of the heterocyclic dimer [ZrCp2{μ-O2BPh}]2 (1); no reaction was observed with the mesityl derivative, (mesBO)3. Compound 1 was also synthesized from the protonolysis reaction between ZrCp2-(CH3)2 and in situ generated phenylboronic acid, PhB(OH)2. This approach was extended to afford the analogous complexes [ZrCp2{μ-O2BAr}]2 (2, Ar = mes; 3, Ar = C6F5) from the corresponding isolable arylboronic acids, ArB(OH)2. The molecular structures of 1-3, determined by X-ray diffraction techniques, revealed a common, dimeric motif consisting of a central "Zr2B2O4" metallacycle. Variations in the bond parameters within the heterocycle are attributed to the differing steric and electronic properties of the aryl substituents at boron.
Santucci,Triboulet
, p. 392,395 (1969)
Increments for 1H and 13C NMR chemical shifts in areneboronic acids
Bruns, Stefan,Sinnwell, Volker,Voss, Juergen
, p. 269 - 272 (2003)
A series of areneboronic acids were studied by NMR spectroscopy. Increments for the 1H and 13C chemical shifts caused by the boronic acid substituent B(OH)2 in areneboronic acids were determined. Copyright
Structural requirements of 1-(2-pyridinyl)-5-pyrazolones for disproportionation of boronic acids
Bae, Yunsoo,Cho, Joungmo,Han, Yohan,Lee, Hwajeong,Lee, Kee-In,Sadu, Venkata Subbaiah
, (2021/11/27)
We observed an unusual formation of four-coordinate boron(III) complexes from the reaction of 1-(2-pyridinyl)-5-pyrazolone derivatives with arylboronic acids in the basic media. The exact mechanism is not clear; however, the use of unprotected boronic acid and the presence of a bidentate ligand appeared to be the key structural requirements for the transformation. The results suggest that base-promoted disproportionation of arylboronic acid with the assistance of the [N,O]-bidentate ligation of 1-(2-pyridinyl)-5-pyrazolone should take place and facilitate the formation of pyrazole di-arylborinate. Experiments to obtain a deeper understanding of its mechanism are currently underway.
METHOD FOR SYNTHESIZING ORGANIC MAGNESIUM COMPOUND, METHOD FOR SYNTHESIZING ORGANIC BORONIC ACID COMPOUND, AND COUPLING METHOD
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Paragraph 0016; 0085-0087, (2021/03/13)
An object is to establish a technology with which an organic magnesium compound can be easily and efficiently synthesized at a low cost with few steps that do not involve a complex chemical method. A method for synthesizing an organic magnesium compound includes, in a reaction solvent, reacting an organic halide represented by General Formula I (Ra—Xa) with a dispersion product obtained by dispersing sodium in a dispersion solvent to obtain an organic sodium compound represented by General Formula II (Ra—Na), and reacting the obtained organic sodium compound with a magnesium halide represented by General Formula III (Mg—(Xb)2) to obtain an organic magnesium compound represented by General Formula IV (Ra—Mg—Xb).