- Synthesis of Fluorine-Containing Aryl(halo)boranes from Potassium Aryl(fluoro)borates
-
Fluorine-containing aryldihalogenoboranes have been obtained by the reaction of boron and aluminum chlorides and bromides with potassium aryltrifluoroborates K[ArBF3] under mild conditions. In a similar way, bis(pentafluorophenyl)halogenoboranes have been synthesized by the reaction with K[(C6F5)2BF2]. The reaction of K[C6F5BF3] with AlBr3 affords a mixture of C6F5BF2 and C6F5BCl2 due to fast conversion of AlBr3 to AlBrCl2. The inductive and resonance parameters of BCl2 and BBr2 groups were calculated.
- Bardin,Prikhod’ko,Shmakov,Shabalin, A. Yu.,Adonin, N. Yu.
-
-
- The preparation of pentafluorophenyldihaloboranes from pentafluorophenylmercurials C6F5HgR and BX3: the dramatic dependence of the reaction direction on the ligand R
-
Abstract: In search of convenient preparations of C6F5BX2 (X = Cl, Br), reactions of C6F5HgR (R = C6F5, C6H5, C2H5, Br and Cl) with BX3 were studied. Under the action of BCl3 the order of the C–Hg bond cleavage is C6F5Hg–C6H5 > C6F5–HgC2H5 > C6F5–HgC6F5 >> C6F5–HgCl. With more reactive BBr3 the sequence is C6F5Hg–C6H5 > C6F5–HgC2H5 ~ C6F5Hg–C2H5 > C6F5–HgC6F5 ≥ C6F5–HgBr. During the study we found the simple way to alkyldibromoboranes which is presented by the preparation of C2H5BBr2 from C2H5HgBr and BBr3. It is the second example of synthesis of alkylmercury derivative in an addition to the earlier reported formation of cyclopropylmercurials from di(cyclopropyl)mercury and BX3. Graphic abstract: [Figure not available: see fulltext.].
- Bardin, Vadim V.,Adonin, Nicolay Yu.
-
p. 1523 - 1531
(2019/07/22)
-
- An axially chiral, electron-deficient borane: Synthesis, coordination chemistry, Lewis acidity, and reactivity
-
An axially chiral dihydroborepine with a binaphthyl backbone and a C 6F5 substituent at the boron atom was prepared by transmetalation from the corresponding tin precursor. This novel motif was structurally characterized by X-ray diffraction analysis as its THF and its PhCN Lewis acid/base complex. 1H NMR measurements at variable temperatures of the former adduct revealed a remarkable dynamic behavior in solution. Several more Lewis pairs with oxygen, nitrogen, carbon, and phosphorus σ-donors were synthesized and analyzed by multinuclear NMR spectroscopy. The determination of the borane's Lewis acidity with the Gutmann-Beckett method attests its substantial Lewis acidity [85% with Et3PO as well as 74% with Ph3PO relative to the parent B(C6F5) 3]. Representative examples of SiH bond activation (carbonyl reduction and dehydrogenative SiO coupling) are included, demonstrating the chemical stability and the synthetic potential of the new chiral boron-based Lewis acid. Copyright
- Mewald, Marius,Froehlich, Roland,Oestreich, Martin
-
supporting information; experimental part
p. 9406 - 9414
(2011/10/09)
-
- From B(C6F5)3 to B(OC6F 5)3: Synthesis of (C6F5) 2BOC6F5 and C6F5B(OC 6F5)2 and
-
The pentafluorophenyl esters of bis(pentafluorophenyl)borinic acid (C 6F5)2BOC6F5 (2) and pentafluorophenylboronic acid C6F6B(OC6F 5)2 (3) have b
- Britovsek, George J. P.,Ugolotti, Juri,White, Andrew J. P.
-
p. 1685 - 1691
(2008/10/09)
-
- A comparative study of base-free arylcopper reagents for the transfer of aryl groups to boron halides
-
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.
- Sundararaman, Anand,J?kle, Frieder
-
p. 134 - 142
(2007/10/03)
-
- Catalyst system for the polymerization of olefins
-
An organometallic compound obtainable by contacting a) a compound having the following formula (I): wherein Ra, Rb, Rcand Rdequal to or different from each other are hydrocarbon groups b) a Lewis acid of formula (II) MtR13??(II) wherein Mt is a metal belonging to Group 13 of the Periodic Table of the Elements (IUPAC); R1, equal to or different from each other, are selected from the group consisting of halogen, halogenated C6-C20aryl and halogenated C7-C20alkylaryl groups; two R1groups can also form with the metal Mt one condensed ring. These compounds are useful as cocatalysts for polymerizing olefins.
- -
-
-
- Synthesis and study of new cyclic boronate additives for lithium battery electrolytes
-
Two novel boronate compounds, 2-(pentafluorophenyl)-tetrafluoro-1,3,2-benzodioxaborole (1) and 2-(pentafluorophenyl)-4,4,5,5-tetrakis(trifluoromethyl)-1,3,2-dioxaborolane (2), have been synthesized as additives for lithium battery electrolytes. These cyclic boronate compounds have a much more significant effect on conductivity enhancement of LiF salt in dimethoxyethene (DME) or ethyl carbonate-dimethyl carbonate (EC-DMC) than either borane or borate additives we previously synthesized. The conductivity of a composite electrolyte containing compound 1 and LiF has reached 9.54 × 10-3 S/cm in DME and 4.79 × 10-3 S/cm in EC-DMC (1:2). This is due to the lower molecular weight and less steric hindrance effects of compound 1. In the case of compound 2, the enhanced performance also comes from the improved solubility in polar solvents. Composite electrolytes containing LiF and either compound 1 or compound 2 have excellent electrochemical stability in the EC-DMC solvent, with respective electrochemical windows of 4.05 and 5.1 V. The composite electrolyte containing LiF and compound 2 shows high cycling efficiency and cyclability in both Li/LiMn2O4 and Li/LiNi0.8Co0.2O2 cells.
- Lee,Sun,Yang,McBreen
-
p. A1460-A1465
(2008/10/08)
-
- (Fluoroorgano)fluoroboranes and -fluoroborates I: Synthesis and spectroscopic characterization of potassium fluoroaryltrifluoroborates and fluoroaryldifluoroboranes
-
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
-
p. 127 - 135
(2007/10/03)
-
- The solid-state structure of bis(pentafluorophenyl)zinc
-
Using the published method of Wiedenbruch, bis(pentafluorophenyl)zinc, 1, was prepared from anhydrous ZnCl2 and 2 equiv. of LiC6F5 in diethyl ether. Base-free 1 was obtained in 60-65% yield by repeated distillation of the initially formed bis(diethyl) ether adduct of 1. The X-ray quality crystals of 1 were obtained from benzene solution. The molecular structure of 1 revealed a near linear geometry for the two-coordinate zinc center (C(1)-Zn-C(7) = 172.6(2)°), typical of monomeric ZnR2 derivatives. In the crystal structure, stacking interactions between C6F5 rings on adjacent molecules is a dominant motif, with ring centroid to ring centroid distances of 3.503 and 3.563 A observed. A weak intermolecular C-F...Zn interaction between F(2) and an adjacent zinc center, as judged by the close contact of 2.849(2) A, also appears to be an important aspect of the crystal structure. Compound 1 is an effective but nonselective C6F5 transfer agent to BCl3; 1: monoclinic, space group P21/n, a = 11.902(2) A, b = 7.732(2) A, c = 13.735(2) A, β = 110.58(1)°, V = 1183.4(4) A3, Z = 4, R = 0.048, Rw = 0.069.
- Sun, Yimin,Piers, Warren E.,Parvez, Masood
-
p. 513 - 517
(2007/10/03)
-