1012-83-5Relevant articles and documents
The preparation of pentafluorophenyldihaloboranes from pentafluorophenylmercurials C6F5HgR and BX3: the dramatic dependence of the reaction direction on the ligand R
Bardin, Vadim V.,Adonin, Nicolay Yu.
, p. 1523 - 1531 (2019)
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.].
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.
Synthesis of cyclopentadienyl-, indenyl-, and fluorenylbis(pentafluorophenyl)boranes as ligands in titanium and zirconium half-sand wich complexes. The crystal structures of C13H9B(C6F5) 2·t-BuNH2, C13H8SiMe3B(C6F5) 2, and {η5-C5H
Duchateau, Robbert,Lancaster, Simon J.,Thornton-Pett, Mark,Bochmann, Manfred
, p. 4995 - 5005 (2008/10/08)
Bis(pentafluorophenyl)boron fluoride (C6F5)2BF·OEt2 (1), readily accessible from BF3·OEt2 and 2 equiv of C6F5MgBr, reacts with fluorenyllithium to give (Flu)B(C6F5)2 (4), while the reaction with indenyllithium leads to the regioisomers 1- and 2-IndB(C6F5)2 5 and 6, which are separated by fractional crystallization. 4 and 5 form crystalline adducts with tert-butylamine. The trimethylsilyl derivatives Flu(SiMe3)B(C6F5)2 (9) and Ind(SiMe3)B(C6F5)2 (10) are similarly prepared. Heating (C6F5)2BF·OEt2 leads to ether cleavage and formation of (C6F5)2BOEt. Treatment of 5 and 6 with Zr(NMe2)4 at room temperature gives indenylzirconium amido half-sandwich complexes; however, the reaction is accompanied by the unexpected exchange of one boron-C6F5 substituent by NMe2, to form 1- and 2-{C9H6B-(C6F5)(NMe 2)}Zr(NMe2)3. Reaction with SiClMe3 affords the trichlorides 1- and 2-{C9H6B-(C6F5)(NMe 2)}ZrCl3. The NMe2 substituent reduces the Lewis acidity of boron, so that donor ligands such as THF or DME coordinate exclusively to zirconium. Whereas 9 and 10 fail to react with group 4 metal chlorides, the cyclopentadienylborane C5H4(SiMe3)B(C6F5) 2 undergoes smooth dehalosilylation with TiCl4 to give {C5H4B(C6F5)2}TiCl 3. Both 2-{C9H6B-(C6F5)(NMe 2)}ZrCl3 and {C5H4B(C6F5)2}TiCl 3 in the presence of low concentrations of AlEt3 are active ethene polymerization catalysts, while under comparable conditions mixtures of AlEt3 and either IndZrCl3 or CpTiCl3 are inactive. The molecular structures of (Flu)B-(C6F5)2·NH2CMe 3, Flu(SiMe3)B(C6F5)2, and {C5H4B(C6F5)2}TiCl 3 have been determined by X-ray diffraction.
