Metals as reducing agents

Reduction of arenes by catalytic hydrogenation was described m Section 114 A dif ferent method using Group I metals as reducing agents which gives 1 4 cyclohexadiene derivatives will be presented m Section 1111 Electrophilic aromatic substitution is the most important reaction type exhibited by benzene and its derivatives and constitutes the entire subject matter of Chapter 12... 

Predict and explain the trend in strengths of the Group 2 metals as reducing agents. 

Read the entire laboratory activity. Form a hypothesis about the relative strengths of these four metals as reducing agents, from strongest to weakest. Record your hypothesis on page 154. 

Do the strengths of the four metals as reducing agents support your... 

We have concentrated our efforts on reducing metal salts in ethereal or hydrocarbon solvents using alkali metals as reducing agents(l 6-54,77). 

The electrochemical hydrodimerization of aromatic aldehydes is more familiar. The essential advantage of this electrosynthesis is the possibility to dispense with the use of metals as reducing agents. The reaction was investigated, for example, by Monsanto for the electrosynthesis of l,2-bis-(hydroxyphenyl)-ethanediol467 -4691 ... 

Going down th motal column, any metal will replace any metal below it in solution. Relative strength of the metals as reducing agents (electron donors) decreases down the table... 

Systems Based on Solid Metals as Reducing Agents... 

Table IX, 7, Catiilytic oxidation of hydrocarbons by dioxygeii in the presence of solid metals as reducing agents.

Cobalt is the only metal in this group whose anionic carbonyl compounds have been investigated in any detail. A carbonyl hydride of rhodium, presumably HRh(CO)4 is formed in low yield as extremely unstable pale yellow crystals by the treatment of rhodium chloride with carbon monoxide in the presence of water and a metal as reducing agent 219). However, this carbonyl hydride of rhodium has not been characterized. Therefore all of the chemistry to be discussed in this section will be cobalt chemistry. 

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