Reactions coordinated ligand

We have delineated viable coordinated ligand reactions and their attendant intermediates for the stoichiometric conversion of CO ligands selectively to the C2 organics ethane, ethylene, methyl (or ethyl) acetate, and acetaldehyde. We now outline results from three lines of research (1) T -Alkoxymethyl iron complexes CpFe(C0)2CH20R (2) are available by reducing coordinated CO on CpFe(C0)3+ (1) [Cp = r -CsHs]. Compounds 2 then form t -alkoxyacetyl complexes via migratory-insertion (i,e. CO... 

Coordinated ligand reactions of this type have been used to synthesize a variety of macrocyclic complexes of the clathrochelate type,382 and somewhat similar reactions have been used quite generally in the macrocycle field.383... 

Coordinated ligands, reactions of, 58, 123 Covalent hydration in heteroaromatic compounds, 4, 1, 43 in nitrogen heterocycles, 20, 117 Current views on some physicochemical aspects of purines, 24, 215 Cyclazines and related N-bridged annulenes, 22, 321... 

The second class of TAM RE AC s inventory includes the reactions between the coordinated ligands and external organic reagents. We divide these reactions into nucleophilic and electrophilic attacks and consider them as acid-base interactions. Table III presents their general description. The nucleophilic attacks are either addition reactions to unsaturated coordinated ligands (Reactions 44-46) or abstraction reactions (usually a proton abstraction, Reactions 47-50). The electrophilic attacks are similarly addition reactions (Reactions 51 and 52) and abstraction reactions (usually a hydride abstraction, Reactions 53-59). Reactions 60 to 63 represent some other intermolecular reactions. 

A major feature of template reactions is geometric formation of the complex brings the reactants into close proximity with the proper orientation for reaction. In addition, complexation may change the electronic stracture sufficiently to promote the reaction. Both are common to all coordinated ligand reactions, but the geometric factor is... 

The mechanism of this reaction resembles that of many coordinated ligand reactions in that the positive charge on the metal draws electrons 11, 16) from the phosphate and further labilizes the weakest link in the chain, which happens in this instance to be the 5 -linkage. 

Os(NH3)6] condenses with acetone in a redox-catalyzed coordinated ligand reaction, impelled by the Os(II)-imine intermediate being strongly stabilized by TT-bonding. Indeed one of the most distinctive features of the chemistry of osmium(II) is its unusually high tendency to 7r-bond. This has a large effect on reactivity, manifested in the various substitution and tautomerization reactions of [Os(NH3)5L] complexes discussed in this section. Kinetic parameters for reactions of the L = 17 -arene series have been conveniently assembled. ... 

This chapter is concerned with coordinated ligand reactions, and notably enhanced reactivity resulting from coordination. It is divided into three sections. The first two deal with coordination complexes of cobalt(III) and other metal centers, while the last section discusses ligand reactivity of organometallic compounds. The emphasis is on stoichiometric reactions catalytic processes are covered in Chapter 14. 

Template reactions and reactions of coordinated ligands occupy similar positions in the Scheme. Almost all template transformations fall into the category of coordinated ligand reactions. At the same time, it needs to be noted that not every chemical transformation of ligands may be classified as a template process. In the case of reactions of coordinated ligands, the metal ion plays an electronic role in... 

The chelate [Ni(L4)] transformation into the macrocyclic product [Ni(L5)Br2] [36, 37] belongs to those coordinated ligand reactions which are also template transformations. The latter are realised as a result of the kinetic coordination template effect with formation of a new chelate ring, whereas the alkylation of [Ni( L4)] with methyl iodide or benzyl bromide is merely a reaction of a coordinated ligand. 

---