Oxidative-addition reactions of transition

Oxidative-addition reactions of transition metal complexes. J. Halpern, Acc. Chem. Res., 1970, 3, 386-392 (66). 

Oxidative-addition reactions of transition metal complexes with the C-H bonds of saturated or unsaturated organic groups, whereby organometal... 

A suitable example is the oxidative-addition reaction of transition metals and their complexes... 

A characteristic and advantageous feature of the oxidative addition reactions of transition metal complexes compared with those of nontransition metal compounds is their reversibility. Grignard reactions cannot be made reversible, but the reverse reaction of oxidative addition is possible with transition metals in many cases. This reverse reaction is called reductive elimination. The ability of the transition metals to donate as well as to accept elec-... 

The unusual feature of oxidative addition reactions of transition metals is the unusually wide range of addends A—B that can be involved, including such normally relatively unreactive molecules as silanes, H2, and even alkanes. Oxidative additions are a very diverse group of reactions in terms of mechanism, and we shall therefore consider each type separately. 

Halpern, J. "Oxidative-Addition Reactions of Transition Metal Complexes." Acc. Chem. Res., 3,386 (1968). 

This chapter deals with references concerning oxidative addition reactions of transition-metal complexes, the closely related reaction of oxidative elimination, and the converse reaction, which is reductive elimination. Oxidative addition is simply what the name implies, e.g. 

The major route to -cyclopropenylium complexes L M(C3R3) (metallatetrahedranes) is by oxidative addition reactions of cyclopropenylium salts to transition metal complexes of groups 5 (V), 6 (Mo, W), 8 (Fe, Ru), 9 (Co, Rh, Ir) and 10 (Ni, Pd, Pt). The addition is frequently accompanied by loss of one or more carbonyl, olefin or halogen auxiliary ligand. Concurrent formation of oxocyclobutenyl complexes by carbonyl insertion into the cyclopropenyl ring is often observed in reactions with group 9 cobalt triad and early transition metal complexes. 

As indicated in Table II, the complexes examined thus far have all contained coordinatively unsaturated dH or d10 metal ions, as has most commonly been the case in oxidative addition reactions of alkyl halides with transition metal substrates. Almost all of the products of these reactions are immediately recognizable as having arisen from an oxidative addition reaction, but in some instances the species isolated, e.g., CF3Au(P3) (59), (CF3)2Pt(COD) (54), and CF3Pt(PEt3)2I (55), were found to be in the same oxidation state as the reagents that had been originally employed. 

V Oxidative addition reactions of coordinatively unsaturated, low oxidation state, transition metal complexes, including established radical reactions especially of Co (II) 89... 

The possibility of the bonding of the hydrogen molecule to transition metals was considered many years ago by E. Singleton in connection with the nature of RuH4(PPh3)2, which readily lost H2 in solution. The compound FeH4(PR3)2 acted similarly and showed an unusual ir band at ca. 2400 cm-1. In addition the oxidative-addition reactions of many d8 complexes, reactions such as... 

Compound [Cr(C0)g(02CCF3)] may be prepared by oxidative substitution of Ag(02CCF3) or Hg(02CCF3)2 on [Cr2(CO)io] (218). Transition metal hydrido complexes have been obtained by oxidative addition reactions of trifluoroacetic acid which often lead to the formation of trifluoroacetato complexes. Equation (3) is an example of such a... 

Oxidative addition reactions of dihydrogen , iodine ", alkyl halides and Hg(CN)2 to carbonyl, olefin or phosphine substituted derivatives of rhodium(I) and iridium(I) have been described. In order to determine the effect on the rate of the reaction, the kinetics of the oxidative addition of Hg(CN)2 to Rh(dik)(P(OPh)3)2 has been studied . A second-order rate law coupled to large negative values of the activation entropy suggest an associative mechanism which probably proceeds via a cyclic three-centred transition state (equation 58). Analogous results were obtained with Ir(dik)(cod) . ... 

Oxidative-addition reactions of 7 transition metal complexes (66)... 

During the past decade, considerable progress has been made in the area of transition metal-catalyzed cleavage and functionalization of the inert C-Cl bond in nonactivated chloroaromatic compounds. This new and important field of chemistry is reviewed in the present chapter, which describes both mechanistic and synthetic aspects of C-Cl activation. Oxidative addition reactions of chloroarenes to complexes of catalytic metals are discussed, along with their applications in a wide variety of reductive dechlorination, nucleophilic displacement, olefin arylation, coupling, and carbonylation reactions. 

Compounds containing bonds between some other elements can react with transition metal complexes via oxidative addition mechanism to produce various derivatives. In some aspects, these reactions are related to the oxidative addition reaction of C-H bonds to low-valent metal complexes and consequently it would be interesting to consider them briefly in this section of the book. Among these processes, the activation of C-C bonds is the most important for us. 

Table 2-2 Oxidative addition reactions on transition metal complexes classification of the adding compounds...

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