- New approach to the generation of aryldifluoroboranes–prospective acid catalysts of organic reactions
-
A new approach for preparation of aromatic and fluoroaromatic difluoroboranes via the interaction between corresponding aryltrifluoroborates and ionic liquids containing tetrachloroaluminate-anion and aluminum chloride has been developed. Catalytic properties of obtained aryldifluoroboranes have been investigated in model reactions of phenols alkylation. The dependence of catalytic properties on both the nature of solvent used and the type of substituents in the aromatic ring of difluoroborane has been established.[Figure presented]
- Shmakov, Mikhail M.,Prikhod'ko, Sergey A.,Bardin, Vadim V.,Adonin, Nicolay Yu.
-
p. 369 - 371
(2018/08/10)
-
- Expanded substrate scope and improved reactivity of ether-forming cross-coupling reactions of organotrifluoroborates and acetals
-
Mixed acetals and organotrifluoroborates undergo BF3· OEt2-promoted cross-couplings to give dialkyl ethers under simple, mild conditions. A survey of reaction partners identified a hydroxamate leaving group that improves the regioselectivity and product yield in the BF 3·OEt2-promoted coupling reaction of mixed acetals and potassium alkynyl-, alkenyl-, aryl- and heteroaryltrifluoroborates to access substituted dialkyl ethers. This leaving group enables the reaction to proceed rapidly under mild conditions (0 °C, 5-60 min) and permits reactions with electron-deficient potassium aryltrifluoroborates that are less reactive with other acetal substrates. A study of the reaction mechanism and characterization of key intermediates by NMR spectroscopy and X-ray crystallography identified a role for the hydroxamate moiety as a reversible leaving group that serves to stabilize the key oxocarbenium intermediate and the need for a slight excess of organodifluoroborane to serve as a catalyst. A secondary role for the boron nucleophile as an activating ligand was also considered. These studies provide the basis for a general class of reagents that lead to dialkyl ethers by a simple, predictable cross-coupling reaction.
- Vo, Cam-Van T.,Mitchell, T. Andrew,Bode, Jeffrey W.
-
supporting information; experimental part
p. 14082 - 14089
(2011/10/12)
-
- Synthesis of dialkyl ethers from organotrifluoroborates and acetals
-
(Chemical Equation Presented) The formation of ethers by C-O bond formation under harsh basic or acidic conditions is an entrenched synthetic disconnection in organic chemistry. We report a strategic alternative that involves the BF3?OEt2
- Mitchell, T. Andrew,Bode, Jeffrey W.
-
supporting information; experimental part
p. 18057 - 18059
(2010/03/26)
-
- Conversion of alkyltrifluoroborates into alkyldichloroboranes with tetrachlorosilane in coordinating solvents
-
Organotrifluoroborate salts are converted rapidly by tetrachlorosilane in nucleophilic solvents such as THF or acetonitrile into organodichloroboranes coordinated with the solvent (see scheme). This reaction completes a sequence from alkylboronic esters via the trifluoroborate salts to reactive alkyldichloroboranes under mild conditions.
- Kim, Byung Ju,Matteson, Donald S.
-
p. 3056 - 3058
(2007/10/03)
-
- A convenient and general approach to alkyl-, alk-1-enyl-, and aryldifluoroboranes
-
A simple and general procedure, especially useful for the small scale preparation of alkyl-, alk-1-enyl-, and aryldifluoroboranes RBF2 was elaborated. Suspensions of the easily available and storable K [RBF3] salts undergo fluoride a
- Frohn,Bailly,Bardin
-
p. 723 - 724
(2008/10/08)
-
- A New Borylation Method for Alkylbenzene and Polystyrene
-
The borylation of alkylbenzenes by Hal2BH (Hal = F, Cl, Br) gives H2 and a mixture of m- and p-alkyl(dihaloboryl)benzenes.In the case of bulky alkyl groups, such as isopropyl, tert-butyl, these are partially split off as R - H and RBHal2.The phenyl groups in polystyrene-divinylbenzene copolymers undergo borylation with Br2BH in a 55percent yield.
- Paetzold, Peter,Hoffmann, Juergen
-
p. 3724 - 3733
(2007/10/02)
-
- A Spectroscopic study of phenylboron halides
-
Phenylfluoroboranes have been prepared by the fluorination ofthe corresponding bromides with titanium tetrafluoride. The infrared spectra of the phenylhaloboranes, R3-nBXn (RC6H5, XF, Cl, Br, I), have been recorded in the 4000-4250 cm-1 region; an assignment of the fundamentals is suggested and characteristic frequency trends are discussed. An evaluation of the spectral data suggests that the structure of phenylfluoroboranes is distinctly different from that of the other halides in the series.
- Nahm, Frederick C.,Rothergy, Eugene F.,Niedenzu, Kurt
-
-