Reactions with transition metal chlorides

Phosgene is formed from the reaction of PdClj with CO in ethanoic anhydride, according to Equation (5.5) [498]  

The dimeric chlorocarbonyl complex, [Pd2(CO)jCl,], formed also from the reaction of CO with PdClj, can react further with CO as exemplified in Equation (5.6) [498]. The formation 

The reaction of PtCl with carbon monoxide is very marked at 140 C [1313] and PtCl. nHjO reacts with carbon monoxide in sulfinyl chloride at 110 C under autogenous pressure according to Equation (5.7) [495]  

In the reactions of carbon monoxide with copper(II) chloride, nickel(II) chloride or silver(l) chloride, thermal decomposition of the salts to give dichlorine, followed by the 

The reaction of CO with AuCl also gives the gold(I) chlorocarbonyl species, Au(CO)Cl, and decomposition of this material proceeds according to equation (5.9) [1100a]  

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The catalysts were synthesized either from the reaction of transition metal chlorides, WCle, M0CI5, OSCI3, R11CI3, IrClj, ReCls with the monomers, or generated by reactions of the transition metal chlorides with alkylating agents, such as Pl Sn, Bu4Sn, (CFh Sn, etc. 

Reactions.—New systems for the reduction of alkyl halides to alkanes include mixtures of lithium aluminium hydride with transition-metal chlorides (such as Ni or Co" chlorides) and some complex metal hydrides of copper, especially the THF-soluble Li4CuHs. Details of the application of sodium cyanoborohydride to the reduction of halides (and sulphonate esters) in dipolar aprotic solvents have been published. Virtually all other functional groups are inert to this convenient, mild, and efficient system, which has been used to develop a one-pot deoxygenation of primary alcohols (Scheme 39) via the iodides. The alternative cyanoborohydride reagents (55) and the polymeric (56) are also discussed. ... 

Alkyne molecules are often linked together in their reactions with transition metal compounds. An early example of this, discovered by Niewland in 1931, was the linear dimerization of ethyne to but-l-en-3-yne, catalysed by copper(I) chloride. The product was for many years an intermediate in the manufacture of chloroprene for synthetic rubber. 

In spite of the usefulness of these complexes, it is generally not possible to cause the satisfactory reaction with transition metals in the metallic state [86] under mild conditions due to their poor reactivity. We have reported that activated metallic nickel, prepared by the reduction of nickel halide with lithium, underwent oxidative addition of benzylic halides to give homocoupled products [45]. We reported that carbonylation of the oxidative adducts of benzylic halides to the nickel proceeded smoothly to afford symmetrical 1,3-diarylpro-pan-2-ones in moderate yields, in which the carbonyl groups of alkyl oxalyl chlorides served as a source of carbon monoxide [43] see Equation 7.5. 

Attempts have been made to catalyze the arrangement of 3-oxaquadricyclane to oxepins with transition-metal complexes.1 32 1 35 When dimethyl 2,4-dimethyl-3-oxaquadricyclane-l,5-dicarboxylate is treated with bis(benzonitrile)dichloroplatinum(II) or dicarbonylrhodium chloride dimer, an oxepin with a substitution pattern different from that following thermolysis is obtained as the main product. Instead of dimethyl 2,7-dimethyloxepin-4,5-dicarboxylate, the product of the thermal isomerization, dimethyl 2,5-dimethyloxepin-3,4-dicarboxylate (12), is formed due to the cleavage of a C O bond. This transition metal catalyzed cleavage accounts also for the formation of a 6-hydroxyfulvene [(cyclopentadienylidene)methanol] derivative (10-15%) and a substituted phenol (2-6%) as minor products.135 The proportion of reaction products is dependent on solvent, catalyst, and temperature. 

The initial step of the reaction with tin(II) chloride reduces the highly oxidized metal in the transition metal anions to low valency cations these are capable of forming stable colored complexes with thiocyanate. 

As shown in Table IV, the highest catalytic activity of metal halides used as Lewis acid for the alkylation reaction of ferrocene with 2 was observed in methylene chloride solvent. Among Lewis acids such as aluminum chloride, aluminum bromide, and Group 4 transition metal chlorides (TiCl4, ZrCU, HfCU), catalytic efficiency for the alkylation decrea.ses in the following order hafnium chloride > zirconium chloride > aluminum chloride > aluminum bromide. Titanium chloride... 

The reaction of bis(silanethiolato) complexes of group 10 metals with transition metal complexes gives the corresponding multinuclear complexes accompanied by the elimination of the silyl chloride (Scheme 14).117,118... 

The synthesis of polyhalide salts, R4NX , used in electrophilic substitution reactions, are described in Chapter 2 and H-bonded complexed salts with the free acid, R4NHX2, which are used for example in acid-catalysed cleavage reactions and in electrophilic addition reactions with alkenes, are often produced in situ [33], although the fluorides are obtained by modification of method I.I.I.B. [19, 34], The in situ formation of such salts can inhibit normal nucleophilic reactions [35, 36]. Quaternary ammonium chlorometallates have been synthesized from quaternary ammonium chlorides and transition metal chlorides, such as IrClj and PtCl4, and are highly efficient catalysts for phase-transfer reactions and for metal complex promoted reactions [37]. 

The cyclopropane 1 reacts with none of the group 1 and 2 metal chlorides. Among early transition metal chlorides, NbCl reacted with i in moderate yield to give the same homoenolate obtained by the reaction of equimolar amounts of titanium homoenolate 2 and NbCl (Scheme 2). TaCl5, CrCl3, MoCls, and WC15 did not give any characterizable products. 

One of the problems encountered with the Werth cell was an increase in resistance with cycling. This may have been caused in part by the /3-alumina reacting with the acidic sodium chloroaluminate melt. Coetzer had the idea of using transition metal chlorides as a positive electrode and chose a basic sodium chloroaluminate melt as the liquid electrolyte. This is compatible with /3-alumina, and a new class of secondary cells based upon the reaction between sodium metal and transition metal chloride has resulted from this work. Collectively, the term Zebra battery is used to describe this new class of cell. 

GICs have been first discovered from the reaction of graphite with sulfuric acid more than 150 years ago.30 In the long history of GICs research, a huge number of compounds have been yielded with a large variety of donors and acceptors, in which alkali metals, alkaline earth metals, transition metal chlorides, acids, and halogens are involved as typical intercalates. 

In 1988, Tilley and coworkers first succeeded in the synthesis of a ruthenium-silene complex by the reaction of Cp Ru(PR3)Cl with a Grignard reagent, and the structure was confirmed by X-ray crystallography (Eq. 9) [10]. They later synthesized an iridium complex in a similar manner (Eq. 10) [11]. Berry synthesized a tungsten-silene complex by treatment of a tungsten-chloride complex with Mg (Eq. 11) [12]. Although reactions of transition metal-silene complexes with Mel, HX, and MeOH have been reported, little is known about their reactivities [11,12]. 

The cyclophosphazenes [NP(OPh)2]2NP OPh)(OC6H4CH2CN-4) and [NP(0C6H4CH2CN-4)2]3 have been used for complexation reactions with a number of 3d-transition metal chlorides. The complexes have been characterized by physical methods and elemental analysis. ... 

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