Trifluoro borate

Two methods for the direct conversion of terminal alkynes to alkynyl(phenyl)iodo-nium tetrafluoroborates have been reported, but their generality has not been documented in the literature. The ter -butylethynyl salt has been prepared by the generation of lithium tert-butylethynyl(trifluoro)borate and its coupling with iodosylbenzene by the standard method (equation 29)80. The treatment of 1-pentyne and phenylacetylene with diphenyl-ju-oxodiiodine(III) bistetrafluoroborate in dichloromethane likewise affords the corresponding alkynyliodonium tetrafluoroborates (equations 30)29. 

Recently, fluoride salts have been found to effect the cross-coupling reactions of 1-alkenyl- and arylboronic acids [53]. The species that undergoes transmetallation is assumed to be the organo(trifluoro)borate ion, RBp3 (Scheme 2-19). 

Arenediazonium salts ArN2Bp4 are an excellent substrate available from aromatic amines for carrying out oxidative addition under mild conditions. The desired cross-coupling with aryl(trifluoro)borates (ArBp3)K is achieved at room temperature with 5 mol% of Pd(OAc)2 or with the paradacycle shown in Eq. 26 (Eq. 46). Biaryl coupling of arene... 

An iridium(I) complex with the l,2-bis(tcrt-butylmethylphosphino)ethane (4) and tetrakis(3,5-bis(trifluoromethyl)phenyl)borate as the counter anion catalyzes the hydrogenation of several acyclic aromatic Ai-arylimines under atmospheric hydrogen pressure at room temperature, giving the desired chiral amines with high-to-excellent enantioselectivities (up to 99%, Fig. 6) [19]. The authors also tested (S )-BINAP (Fig. 1) and (/ )-Ph-PHOX (PHOX = 2-[2-(diphenylphosphino) phenyl]-4,5-dihydrooxazole) hgands with lower enantioselectivities [19]. Both steric and electronic properties of the ligand and the combination with the BArF anion are in the base of the efficacy of this catalytic system. On the other hand, attempted hydrogenations of Ai-(2,2,2-trifluoro-l-phenylethylidene)aniline and M-(l,2,2-trimethyl-propylidene)aniline under the same conditions resulted in... 

Bromo-3,4,5-trifluorobenzene Benzene, 5-bromo-1,2,3-trifluoro- (13) (138526-69-9) Trimethyl borate Boric acid, trimethyl ester (8,9) (121-43-7)... 

C30H24O4P2W, Tungsten(O), tetracarbonyl 1,2-bis(diphenylphosphino)ethane -, 34 108 C32Hi2BF24Na, Borate, tetrakis(3,5-bis(trifluoro-methyl)phenyl)-, sodium salt, 34 5 C32H29FeNP2, Iron(II), cyano( ) -cyclopentadie-nyl)-l,2-bis(diphenylphosphino)ethane-, 34 161... 

Regio- and stereo-selective allylation of sulfonylimines has been carried out with trifluoro(allyl)borates and allylstannanes, using palladium-pincer complexes as catalysts.47 Syn products predominate, in contrast to the corresponding reaction of aldehyde electrophiles DFT calculations have been employed to probe the mechanistic differences. 

Potassium trifluoro(organo)borates such as ArBF3K couple with benzaldehydes to give carbinols using the catalytic combination of Rh(H2C=CH2)2Cl2 and Bu P, in toluene-water mixtures at 60 °C.248 The reaction tolerates a wide range of functionality and works well for hindered benzaldehydes, and even for aliphatic aldehydes. 

F-Teda BF4 (708 mg, 2.5 mmol) was added to a solution of potassium trifluoro[( )-2-phenylvinyl]borate (210 mg. 1 mmol) in MeCN (10 mL) and the resulting mixture was stirred at rt for 48 h. The solvent was evaporated and the residue was treated with I.OM NaOH (5mL). Extraetion with Et20 (3xl0mL), followed by purifieation by flash column chromatography (silica gel. hexanes/EtOAc 7 3) yielded pure product as an off-yellow powder yield 164 ing (82%). 

BORANE, COMPD. WITH N2H4 see HGU025 BORANE with DIMETHYLAMINE (1 1) see DOR200 BORANE, TRIFLUORO-, DIHYDRATE see BMG800 BORATES, TETRA, SODIUM SALT, anhydrous (OSHA) see DXG035... 

Protodesilylation of allyl- or aryl-substituted trialkylsilanes with an acid partner is a cleaner method, producing propene or an aromatic hydrocarbon as a volatile inert byproduct. Although some methods of isolation have been reported, they can usually be prepared in situ in aprotic media and employed without further purification. Methods of preparation of representative organosilicon Lewis acids, la, trimethylsilyl bis(trifluoro-methanesulfone)imide (7) [9], trimethylsilyl perchlorate (6a) [10], iodotrimethylsilane, and trimethylsilyl tetrakis(trifluoromethanesulfonyl)borate [11] are described below. In principle, these analogs are also accessible in a similar manner (Table 1) [2d]. 

Arenediazonium ion reactions often are complex.61 Benzenediazonium fluoro-borate in 2,2,2-trifluoro ethanol (TFE), for example, decomposes by first-order kinetics to give a mixture consisting largely of the ether (62%) formed by solvolysis and fluorobenzene (34%) resulting from reaction with fluoroborate ion. Addition of pyridine changes the kinetic order and gives rise to additional products.62 The same diazonium ion solvolyzes faster in TFE than in water. Because water is a better nucleophile than TFE, it is likely that a nucleophile is not involved in the rate limiting step of the reaction.63 ... 

Fluorinated aryl borates have emerged as versatile organometaiiic WGA reagents in the last decade. Their availability through reliable preparative procedures, or commercial sources, as well as their excellent solubility and stability properties, has made fluorinated aryl borates the anion of choice in many organometaiiic research programs. Two derivatives, in particular, are extremely common tris(pentafluorophenyl)borane derivatives and tetrakis(3,5-trifluoro-methylphenyl)borate (see Figure 18). 

Spectral (i.r. and Raman) assignments for the trifluoro(trifluoromethyl)borate anion in K+[CFs BFa] have been made on the basis of Cat> symmetry, using both i B and B compounds Urey-Bradley force constants were computed for the CFa and BFa groupings and compared with those derived from studies on CaFe and BF4-. ... 

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