69464-76-2Relevant academic research and scientific papers
Photochemical Generation of Chiral N,B,X-Heterocycles by Heteroaromatic C?X Bond Scission (X=S, O) and Boron Insertion
Mellerup, Soren K.,Li, Cally,Radtke, Julian,Wang, Xiang,Li, Quan-Song,Wang, Suning
, p. 9634 - 9639 (2018)
Chiral organoboron compounds with a chelate backbone and mesityl/heterocycle substituents (thienyl, furyl, and derivatives thereof) undergo a quantitative phototransformation that yields rare, chiral N,B,X-containing heterocycles, such as base-stabilized
Synthesis of arylboronates by boron-induced ipso-deantimonation of triarylstibanes with boron trihalides and its application in one-pot two-step transmetallation/cross-coupling reactions
Yasuike, Shuji,Nakata, Kazuhide,Qin, Weiwei,Matsumura, Mio,Kakusawa, Naoki,Kurita, Jyoji
, p. 9 - 16 (2015/05/13)
The reaction of triarylstibanes (1) with boron trihalides (BCl3, and BBr3) afforded arylboron dihalides (2) by utilizing all the three aryl groups on the antimony. Boron intermediates (2) were transformed to arylboronates (3) in good to excellent yields by treatment with methanol and 1,3-propanediol. Further, the Pd-catalyzed reactions of 2 with organic halides such as 1-bromonaphthalene and benzoyl chloride in the presence of H2O afforded the corresponding cross-coupling products, unsymmetrical biaryls (4) and ketones (5), in moderate to good yields. The potential energy surfaces for the transmetallations of triarylstibanes (1) with BCl3 affording 2 were determined by molecular orbital calculations. The analyses of substituent effects on theoretically calculated reactivities showed the importance of the resonance effects of the ring substituents on these transmetallations.
Porphyrinylboranes Synthesized via Porphyrinyllithiums
Fujimoto, Keisuke,Yorimitsu, Hideki,Osuka, Atsuhiro
, p. 11311 - 11314 (2015/08/03)
As the most nucleophilic porphyrins, meso- or β-lithiated porphyrins were generated by iodine-lithium exchange reactions of the corresponding iodoporphyrins with n-butyllithium at -98°C. Porphyrinyllithiums thus prepared were used for synthesis of dimesitylporphyrinylboranes through reactions with fluorodimesitylborane. The boryl groups proved to serve as an electron-accepting unit to alter the photophysical and electrochemical properties. In addition, 5-diarylamino-15-dimesitylboryl-substituted donor-accepter porphyrins showed increased intramolecular charge-transfer character in the S1 state. Furthermore, the reaction of β-lithiated porphyrin with dichloromesitylborane provided a boron-bridged porphyrin dimer, which exhibited a conjugative interaction between two porphyrin units through the vacant p-orbital on the boron center. Porphyrinyllithiums were generated by iodine-lithium exchange of the corresponding iodoporphyrins. The porphyrinyllithiums were useful for the synthesis of a series of porphyrinylboranes through reactions with suitable haloboranes. The boryl groups served as electron-accepting units to alter the photophysical and electrochemical properties. A B,N-substituted donor-accepter porphyrin showed an increased intramolecular charge-transfer character in the S1 state. A boron-bridged porphyrin dimer exhibited a conjugative interaction between two porphyrin units through the vacant p-orbital at the boron atom.
A comparative study of base-free arylcopper reagents for the transfer of aryl groups to boron halides
Sundararaman, Anand,J?kle, Frieder
, p. 134 - 142 (2007/10/03)
A comparative study on the reactivity and selectivity of arylcopper species in reactions with boron halides was performed. Mesitylcopper reacts with BX3 (X=Cl, Br) in toluene at low temperature under highly selective formation of the monosubstituted boranes MesBX2. The dimesitylboranes Mes2BX are gradually formed with a twofold excess of the organocopper reagent at elevated temperature. In contrast, pentafluorophenylcopper shows a tendency for formation of B(C6F5) 3 in reactions with BX3 irrespective of the stoichiometry used, suggesting a strong impact of electronic factors on the selectivity of the aryl transfer reaction. New procedures for the synthesis of the pentafluorophenylboron halides C6 F5BX2 (X=Cl: 57%; X=Br: 62%) and of tris(pentafluorophenyl)borane (80%) and related mixed-substituted triarylboranes from the base-free isolable pentafluorophenylcopper precursor have been developed.
Flash Vacuum Pyrolysis of o-Alkylaryl- and Arylalkylchloroboranes. - Synthesis of Benzoannulated Boracycloalkenes
Schacht, Wolfgang,Kaufmann, Dieter
, p. 1331 - 1338 (2007/10/02)
The dichloroorganylboranes chosen as pyrolytic starting materials were synthesized upon treatment of the corresponding triorganylboroxines and aryltrimethylsilanes (giving 3, 4) or the tetraorganylstannanes (giving 9-12, 17-20) with boron trichloride.At 700 deg C the flash vacuum pyrolysis of the dichloro(2-ethylphenyl)boranes 10 and 4 led to 1-boraindanes 21 and 22 selectively.The dichloro-2-tolylborane (9), the B-dimethylamino derivative, and mesitylboranes like 3 were completely stable upon pyrolysis.Pyrolyzing the isopropylphenylborane 12 1,5-elimination exclusively took place yielding 26, while pyrolysis of propylphenylborane 11 led to a mixture of boraindane 29 and boratetraline 30.To exclude such competitive reactions, some arylalkyldichloroboranes were pyrolyzed.At 750 deg C dichloro(2-methylbenzyl)borane (18) exclusively yielded oligomeric 2-chloro-2-boraindane (31).At 950 deg C even the pyrolysis of benzyldichloroborane (17) succeeded in a 1,4-elimination reaction yielding the eight-membered 2H-benzoborete dimer 34.The inversion barrier of 34 is ΔG(excit.)228 = 10.3 kcal mol-1, determined by NMR spectroscopy.The pyrolysis of the next-higher homologous dichloroorganylborane 19 yielded a boraindane 21 and a noncyclic diorganylborane 38 by a dehydroboration/hydroboration pathway.Both reaction types also took place when pyrolyzing dichloroborane (20): cyclization under formation of a five-membered ring system 39, formed upon attack of an aromatic C-H bond exclusively, and formation of an open-chain chlorodiorganylborane 40.
