Lithium,2,3,5,6-tetrakis phenyl

Through a rather complicated sequence of meanwhile fully understood reaction steps ethyl benzoate and lithium bis(trimethylsilyl)phosphanide form tris(l,2-dimethoxyethane-0,0 )-lithium 3-phenyl-l,3-bis(trimethylsilyl)-l,2-diphosphapropenide and 3,5-diphenyl-l,2-bis(tri-methylsilyl)-l,2,4-triphospholide. X-ray structure determinations on orange or green, metallically lustrous, crystals show the compoxmds to be ionic in the solid and to contain a 1,2-diphosphaallyl and a 2-phosphaallyl anion, respectively. Dark red tetrakis(tetra-... 

Flginre 8 Co-ordination of the ions in lithium tetrakis(dimethylphenylsilyl)mercurate(n) only the carbon atoms forming die cages around the ions are included the C(2) tmd C(2 ) carbons are methyl carbons, while all other carbons are phenyl carbons (Reproduced by permission from J. Amer. Chem. Soc., 1975, 97, 6261)... 

This complex is not the actual catalyst for the hydrovinylation, but needs to be activated in the presence of a suitable co-catalyst. The role of this additive is to abstract the chloride ion from the nickel centre to generate a cationic allyl complex that further converts to the catalytically active nickel hydride species. In conventional solvents this is typically achieved using strong Lewis acids such as Et2AlCl. Alternatively, sodium or lithium salts of non-coordinating anions such as tetrakis-[3,5-bis(trifluoromethyl)phenyl]borate (BARF) can be used to activate hydrovinylation... 

The reaction of diphenyl tellurium dichloride with phenyl lithium yielded tetraphenyl tellurium1. Bis[trifluoromethyl] tellurium dichloride and bis[trifluoromethyl] cadmium reacted to produce tetrakis[trifiuoromethyl tellurium2. 

A mixture of 6-bromo-4-(tri luoromethanesulfonyloxy)-5,8-dimethoxy-quinoline (1.35 g, 3.25 mmol), trimethyl[2-[(l,l-dimethylethoxycarbonyl)-amino]phenyl]tin (1.68 g, 4.70 mmol), lithium chloride (330 mg, 7.80 mmol), copper(I) bromide (25 mg, 0.17 mmol), and tetrakis(triphenylphosphine)palla-dium (0) (180 mg, 0.16 mmol) in dioxane (60 cm ) was heated at 90 °C for 60 h. After being cooled to rt, the mixture was partitioned between EtOAc and a 5 % aqueous ethylenediamine solution to remove any copper species, completely. After the usual work up, the residue was chromatographed (1.5 1 hexanes -EtOAc) to yield the title compound as a white solid (952 mg, 64%, several other fractions contained the title compound contaminated with 6-bromo-5,8-di-methoxy-4-methylquinoline) mp 166-168 °C. 

Surprisingly, the reaction of phosphaalkynes with lithium bis(trimethylsilyl)phosphanide may be transferred to alkynes. With diphenylethyne, for example, tetrakis(tetrahydrofuran)lithium 2,3,4,5-tetraphenylphospholide has been isolated in about 60 % yield from a THF solution (Eq. 17) again, the fate of both trimethylsilyl substituents remains unknown. The solid is built up of discrete tetrakis(tetrahydrofuran)lithium cations and planar phospholide anions (space group P1 w7 2-value 0.173 P-C 176 C-C 140 to 143 pm) the phenyl groups are tilted out of the C4P plane by angles of 47-65° [39]. 

Li(OEt2)(p3-Ph) 4] tetrakis[(ethoxyethane)(p3-phenyl)lithium], or tetrakis[(p3-benzenido)(ethoxyethane)lithium]... 

Perfluorinated organosilicon compounds such as tetrakis(pentafluoro-phenyl)silane can be prepared from silicon tetrachloride and (pentafluoro-phenyl)-magnesium bromide or -lithium.278... 

ALKENES Allyl dimethyldithiocarbamate. Bis(t -cyclopentadienyl)niobium trihydride. Cyanogen bromide. Di-n-butylcopperlithium. a,o-Dichloromethyl methyl ether. 2,3-Dimethyl-2-butylborane. N,N-Dimethyl dichlorophosphoramide. Diphenyl diselenide. Di-n-propylcopperlithium. Ferric chloride. Grignard reagents. Iodine. Lithium phenylethynolate. Lithium 2,2,6,6-tetramethylpiperidide. Methyl iodide. o-Nitro-phenyl selenocyanate. Propargyl bromide. rra s-l-Propenyllithium. Selenium. Tetrakis(triphenylphosphine)palladium. Titanium(IH) chloride. Titanium trichloride-Lithium aluminum hydride. p-Toluenesulfonylhydrazine. Triphenylphosphine. Vinyl-copper reagents. Vinyllithium. Zinc. 

P Aug FgReC 114H io6< Phosphate(l—), hexa-fluoro-, tetrahydridobis[tris(4-methyl-phenyl)phosphinc]tetrakis[(triphenyl-phosphine)gold rhenium(l +), 29 292 P,Li3, Lithium heptaphosphide, (LijP,), 27 227... 

Vanadium.— Reaction of pentafluorophenyl-lithium with vanadium tetrachloride in diethyl ether and hexane at — 70 °C yields tetrakis(pentafluoro-phenyl)vanadium, which crystallizes as the dietherate at 0 °C. It is very moisture sensitive, yielding pentafluorobenzene and a trace of perfluoro-biphenyl, and with mercuric chloride in tetrahydrofuran yields bis(penta-fluorophenyl)mercury (95%). 

Cross-coupling of methoxyallenyl-lithium compounds and iodobenzene may be accomplished when it is catalysed by tetrakis(triphenylphosphine)pal-ladium. However, only one example for each sequence to give an alkyl styryl ketone and phenyl vinyl ketone was reported [equations (29) and (30)J. ap-... 

The simple structures of THF-solvated 2,6-di(l-naphthyl)phenyllithium and 2,6-di(phenyl)phenyhithium have been reported to be respectively mono- and dinuclear. The solid-state structure of (DME Li)2C4(SiMc3)4 has recently been found to incorporate DME-chelated metal centres above and below a four-membered, flat cyclobutadienyl ring (within which mean O-C = 1.495 A). A similar structure has also been revealed for (DME Li)2C4Ph2(SiMe2CH2)2. The two electron reduction of 2,3-bis(dimethylsilyl)-l,l,4,4-tetramethyl-l,4-disila-1,4-dihydronaphthalene using elemental lithium affords a complex in which the two metal centres bridge an isolated C = C bond. In the same way, alkali metal ions reside above and below each of two C=C interactions in the tetrametal salt which results from the treatment of 2,3,6,7-tetrakis(trimethylsilyl)-l,l,4,4,5,5,8,8-octamethyl-1,4,5,8-tetrasila- 1,4,5,8-tetrahydroanthracene with Li(0). ... 

Tetrakis(pyridine)iron(II) chloride (0.500 g, 1.13 mmol, 1.00 equiv.) is suspended in tetrahydrofuran (3.0 mL) at 23 °C. In a separate vial, 2-[(dimethylamino)methyl]phenyl-lithium (0.319 g, 2.26 mmol, 2.00 equiv.), is dissolved in tetrahydrofuran (2.5 mL) at 23 C. Both vials are cooled to -40 °C and the solution of 2-[(dimethylamino)methyl]-phenyllithium is added dropwise to tetrakis(pyridine)iron(lI) chloride. The reaction mixture is stirred at -40 C for 30 min and then warmed to 23 C and stirred for 2 h. The solvent is removed in vacuo, benzene (15 mL) is added, and the dark purple mixture is filtered through a pad of Celite, eluting with benzene. The solvent is removed in vacuo to afford bis[2-(A, A -dimethylaminomethyl)-phenyl-C,N]pyridineiron(II) 0.365 g (80%). 

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