Ferrocenyl bromide

To a mixture of vinyl bromide (40 mmol) and the catalyst dichloro-[(R)-Af,N-dimethyl-l-[(.S)-2-(diphenylphosphino)ferrocenyl]ethylamine]-palladium(n) (0.2 mmol) was added an ethereal solution of [a-(trimethyl-silyl)benzyl]magnesium bromide (0.6-1 m, 80 mmol) at —78 °C. The mixture was stirred at 30 °C for 4 days, and then cooled to 0 °C and hydrolysed with dilute aqueous HC1 (3 m). The organic layer was separated, and the aqueous layer was re-extracted with ether. The combined organic extracts were washed with saturated sodium hydrogen carbonate solution and water, and dried. Concentration and distillation gave the chiral allylsilane (79%, 66% ee), b.p. 55°C/0.4mmHg. 

Diphenyl-propyl- 518 Diphenyl- -tetrafluoroborat 85 Dipropyl- -perchlorat 85 Dipropyl-phenyl- 518 Triphcnyl-518f, 588, 649 Triphenyl- -bromid 85 Tri propyl - 518 Tris-[ferrocenyll- 649... 

Ferrocenyl diphosphine core-functionalized carbosilane dendrimers have been prepared as ligands for homogeneous catalytic reactions applied in a CFMR by Van Leeuwen et al. [20,21,67,68]. The syntheses of these dppf-like ligands (Go-G2)-17 were performed using carbosilane dendritic wedges with an aryl bromide as focal point. These wedges were coupled to the core via quenching of the lithiated species with ferrocenyl phosphonites (Scheme 11). 

An addition to the literature on the arylation of protected hydrazines was recently contributed by Skerlj et al. [186]. In addition to the reactions of halopyridines with tert-butyl carbazate (H2NNHBoc) discussed in Section 4.3.2.3, these authors have reported the reaction of electron-deficient aryl bromides with this substrate. Reactions occurred when using DPPF or the ferrocenyl 11 as the ligand along with CS2CO3 as the base at temperatures of 100-110 °C. 

One key goal of catalyst development is to move from the more expensive alkyl and aryl iodides and bromides to the cheaper chlorides and the environmentally more desirable tosylates. The latter tend to react less well bnt the nse of basic, bulky ligands like P(tBn)3 and a nnmber of ferrocenyl-substituted phosphines has improved the situation. 

Azidoferrocenes have been synthesized by treating bromoferrocenes with azide ion and cupric bromide in dimethylformamide . Thus ferrocenyl azide (165) was obtained in 98% yield from bromoferrocene and 1, T-ferrocenylene diazide (166) was prepared from the corres-... 

A different solution to the use of hydrophilic ligands is possible for the Suzuki reaction of aryl bromides in water. The complex Pd(dppf)Cl2 (dppf = l,l -bis(diphenylphosphino)ferrocene, 102) was indeed an extremely active catalyst, simply using an aqueous solution of K2CO3 as the reaction medium. Excellent yields and TONs up to 870 000 were recorded for the reaction of l-bromo-4-nitrobenzene and phenylboronic acid at 110 °C for 48 h (Scheme 1.66). The choice of the ferrocenyl ligand in Pd(dppf)Cl2, a weakly electron-... 

Stable organosilver derivatives of chloroferrocene have been prepared by the reaction of the corresponding boronic acid with silver salts in aqueous ammonia solution (equation 32)86 - 88 2-Silver(dimethylaminomethyl)ferrocene has been obtained by trans-metallation between silver bromide and the corresponding lithium ferrocenyl compound89. 

Lithium diisopropylamide (2 M in tetrahydrofuran, 1.35 mL, 2.70 mmol, 1.1 equiv.) was added dropwise at —78 °C to a solution of (S)-ferrocenyl-/ -tolylsulfoxide (2) (793 mg, 2.45 mmol) in dry tetrahydrofuran (15 mL). After 30 minutes stirring, zinc bromide solution (1.3 M in tetrahydrofuran, 2.51 mL, 3.26 mmol, 1.3 equiv.) was slowly added and the mixture was allowed to warm to room temperature. After 1 hour the solvent was evaporated in vacuo and the resulting residue was dissolved in dry tetrahydrofuran (10 mL). Pd(dba)2 (61.2 mg, 5 mol%) and tris-o-furylphosphine (49.2 mg, 10 mol%) were dissolved in dry tetrahydrofuran (3 mL) and stirred for 10 minutes. A solution of (2-iodophenyl)diphenylphosphine (633 mg, 1.63 mmol, 0.67 equiv.) in dry tetrahydrofuran (2 mL) was added and the mixture was stirred for an additional 10 minutes. The solution of the ferrocenyl zinc compound was added and the reaction mixture was stirred at 65 °C for 16 hours. The solution was quenched with water, the aqueous phase was extracted with diethyl ether (3 x 50 mL), the combined organic phases were washed with brine and dried over magnesium sulfate. The solvent was removed under reduced pressure. 

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