Gatterman-Koch

GATTERMAN - KOCH Cartionylation Synthesis of aromatic aldehydes or ketones using cyanide salts or CO - HCI and Lewis adds. 

Gasoline, manufacture of, 99-100 octane number of, 100 Gatterman-Koch reaction. 596 Gauche conformation, 95 butane and, 95-96 steric strain in, 96... 

Another method, formylation with CO and HCl in the presence of AICI3 and CuCl (the Gatterman-Koch reaction), is limited to benzene and alkylbenzenes. ... 

The decarbonylation of aromatic aldehydes with sulfuric acid" is the reverse of the Gatterman-Koch reaction (11-16). It has been carried out with trialkyl- and trialkoxybenzaldehydes. The reaction takes place by the ordinary arenium ion mechanism the attacking species is H and the leaving group is HCO, which can lose a proton to give CO or combine with OH from the water solvent to give formic acid." Aromatic aldehydes have also been decarbonylated with basic catalysts." When basic catalysts are used, the mechanism is probably similar to the SeI process of 11-38. See also 14-39. 

Gatterman-Koch synthesis org chem A synthesis of aldehydes aldehydes form when an aromatic hydrocarbon is heated in the presence of hydrogen chloride, certain metallic chloride catalysts, and either carbon monoxide or hydrogen cyanide. gad-3r-man kok, sin-th3-s3s ... 

This reaction is known as Gatterman-Koch reaction. 

Arenes can be formylated by generating the active intermediate, CfeC—H, from reagents other than HCOCl. The Gatterman-Koch reaction uses a high-pressure gaseous mixture of CO and HCl. 

Gatterman-Koch Reaction (see under Gatterman Reaction)... 

Aromatic aldehydes may be obtained by passing a mixture of carbon monoxide and hydrogen chloride into the aromatic hydrocarbon in the presence of a mixture of copper(i) chloride and aluminium chloride which acts as a catalyst (Gatterman-Koch reaction). It is probable that the electrophilic species is the ... 

The Gatterman-Koch formylation is unsuitable for the preparation of aldehydes from phenols and phenolic ethers owing to the formation of complexes with the Lewis acid. 

The Gatterman aldehyde synthesis employs hydrogen cyanide and unlike the Gatterman-Koch procedure, this method is successful in the case of phenols and phenolic ethers, although only the more reactive hydrocarbons are formylated... 

Show how you would use the Friedel-Crafts acylation, Clemmensen reduction, and/or Gatterman-Koch synthesis to prepare the following compounds ... 

The Gatterman-Koch synthesis is a variant of the Friedel-Crafts acylation in which carbon monoxide and HC1 generate an intermediate that reacts like formyl chloride. Like Friedel-Crafts reactions, the Gatterman-Koch formylation succeeds only with benzene and activated benzene derivatives. 

This reaction, known as the Gatterman-Koch reaction, does not work with phenolic or amino aromatic species due to complex formation with the Lewis acid. It does work well with aromatic hydrocarbons and is used industrially to prepare benzaldehyde and, as here, p-tolualdehyde. 

Gatterman-Koch hydrocarbons C0,HCI,AICI3.CuCI H-C=0+ ArCHD... 

Another commercial aldehyde synthesis is the catalytic dehydrogenation of primary alcohols at high temperature in the presence of a copper or a copper-chromite catalyst. Although there are several other synthetic processes employed, these tend to be smaller scale reactions. For example, acyl halides can be reduced to the aldehyde (Rosemnund reaction) using a palladium-on-barium sulfate catalyst. Formylation of aryl compounds, similar to hydrofomiylation, using HCN and HQ (Gatterman reaction) or carbon monoxide and HQ (Gatterman-Koch reaction) can be used to produce aromatic aldehydes. 

The formyl cation HCO+ (vco at 2110 cm ) is generated from CO under pressure in the presence of HF/SbFs. Concentrated sulfuric acid or the HCl/CuCl system, activates carbon monoxide toward the electrophilic attack on aromatic hydrocarbons to form aromatic aldehydes (Gatterman-Koch reaction). Branched carboxylic acids are obtained from alkenes and CO in the presence of concentrated sulfuric acid (Koch process) (equation 3). ... 

The electrophilic formylation of arenes with CO in the presence of acids (Gatterman-Koch conditions) is an efficient method for preparing aromatic aldehydes. HF-SbFs-SO2CIF is the most active system for this reaction [82]. It has been demonstrated that even diformylation can be achieved on polymeric aromatics such as biphenyl with the use of fluoroantimonic acid (Eq. 36) [83]. 

Gabriel synthesis, 403 Gatterman reaction, 429 Gatterman-Koch reaction, 307 Gauche conformation, 53, 170, 275 Geometric isomerism, 88 ... 

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