Diazonium carboxylates halides

Nitro -NO, alkyl (-R) and acyl RCO-) groups can readily be added by electrophilic substitution and can then be converted to amino, carboxylic acid, and alkyl groups, respectively. Once the amino and carboxylic acid groups have been obtained, they can be further converted to a large range of other functional groups like secondary and tertiary amines, amides, diazonium salts, halides, nitriles, esters, phenols, alcohols, and ethers. 

The original reaction procedures have steadily been extended and improved, and an overwhelming number of catalyst systems are now known. Besides aryl halides, many additional substrates, for example aryl triflates, diazonium salts, sulfonyl and aroyl halides, carboxylic and phosphonic acids, and even arenes have been used as... 

Reactions with Diazonium Salts, Organic Halides, and Carboxylic Acids... 

Now, let us take a simple functional group such as an OH and substitute it on our carbon atom. The carbinol we now have is capable of yielding only one C-C bond by way of substitution or one unsaturation on our carbon by means of elimination. Alcohols should then be classified under the FN = 1 group. Other oxygen based substituents such as ethers, carboxylic and sulfonic esters, and other heteroatom-containing derivatives such as amines and sulfides behave similarly, as long as we have only one of the heteroatoms substituted on our central carbon. By the same token, alkyl halides, diazonium salts, and even the carbenium ion itself are all capable of giving only one C-C bond with carbon... 

Reaction of aliphatic amines1160 or amino carboxylic acids1161 with nitrosyl halides (NOX) leads to halides, and not, as in the analogous reaction of aromatic amines, to diazonium halides. 

The free carboxylic acid VI is obtained from chloromalonic acid and the corresponding diazonium halide... 

Besides the traditional coupling between alkenes and aryl (vinyl) halides, other functionalized aryl derivatives can also couple with alkenes in the Heck reaction, including aryl silanes,stannanes, bismuth, antimony,triflates, boric acid, phosphonic acid, carboxylic acid, and diazonium salt. ... 

In addition to diazonium salts, there are many other species that are able, once electrochemicaUy activated, to modify the surface with aromatics, unsaturated and saturated groups. These surface modifications can be achieved by (i) oxidation (amines, hydrazines, alcohols, carboxylates, carbamates, carbanions, Grignard reagents) (ii) reduction, some being closely related to diazonium salts (iodoniums, sulfonium) and other different species (vinylics, alkyl halide) (iii) spontaneously, chemically or pho-tochemically (alcenes, azides, peroxides). Note that electrochemical oxidation methods can be applied only to the materials that can withstand quite positive potentials such as carbon or Pt. This section will describe these modifications [357]. 

Two methods for converting carboxylic acids to esters fall into the mechanistic group under discussion. One of these methods is the reaction of carboxylic acids with diazo compounds, especially diazomethane. The second is alkylation of car-boxylate anions by halides or sulfonates. The esterification of carboxylic acids with diazomethane is a very quick and clean reaction. The alkylating agent is the extremely reactive methyl diazonium ion, which is generated by proton transfer from the carboxylic acid to diazomethane. The collapse of the resulting ion pair with loss of nitrogen is extremely rapid ... 

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