Gattermann Koch reaction

Gattermann and Koch were not able to prepare formyl chloride but instead discovered that CO and HCI in the presence of AlCb and cuprous chloride behave like the hypothetical formyl chloride and react with toluene in a manner similar to other acid chlorides (Eq 1.13). 

The Gattermann-Koch reaction can be carried out under two major types of conditions i.e. at atmospheric pressure where CU2CI2 is necessary as a promoter or complexing agent and secondly at high-pressure where the presence of CU2CI2 is not necessary. The Gattermann-Koch aldehyde synthesis is a suitable method for the preparation of simple aromatic aldehydes such as benzaldehyde and tolualdehyde. Formylation of ortho and 

In the di-substituted benzene series o- and m-xylene give the expected products. However, p-xylene undergoes isomerisation to furnish 2,4-dimethylbenzaldehyde. The tri-substituted benzene series i.e. mesitylene and pseudo-cumene yield normal formylation products. Tetralin and di-isopropyltetralin in the naphthalene series are reported to undergo Gattermann-Koch formylation whereas naphthalene itself is formylated in the modified reaction using HF and BF3 as catalyst. 

Carbonylation of halogenated- and alkyl-substituted benzenes in good yield, involving the use of catalytic amounts of aqueous hydrochloric acid, has recently been reported (Table 1.5). 

Entry Substrate (mmol) AICI3 (mmol) Solvent CO Press, (psi) Temp (°C) Time (h) Aldehyde Yield (%) 

Tanaka, M. Fujiwara, M. Ando, H. Souma, Y. Chem. Commun. 1996, 159. 

Formylation of arenes using carbon monoxide and hydrogen chloride in the presence of aluminum chloride under high pressure. 

Gattermann, L. Koch, J. A. Ber.1897, 30, 1622-1624. Ludwig Gattermann (1860-1920) was bom in Freiburg, Germany. His textbook, Die Praxis de or-ganischen Chemie (1894) was one of his major contributions to organic chemistry. Crounse, N. N. Org. React. 1949, 5, 290-300. (Review). 

Solladie, G. Rubio, A. Carreno, M. C. Garcia Ruano, J. L. Tetrahedron Asymmetry 1990,/, 187-198. 

Name Reactions, 4th ed., DOI 10.1007/978-3-642-01053-8 Springer-Verlag Berlin Heidelberg 2009 

Name Reactions A Collection of Detailed Mechanisms and Synthetic Applications, DOl 10.1007/978-3-319-03979-4 117, Springer International Publishing Switzerland 2014 

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Gattermann-Koch reaction Formylation of an aromatic hydrocarbon to yield the corresponding aldehyde by treatment with CO, HCl and AICI3 at atmospheric pressure CuCl is also required. The reaction resembles a Friedel-Crafts acylation since methanoyl chloride, HCOCl, is probably involved. 

By passing a mixture of carbon monoxide and hydrogen chloride into the aromatic hydrocarbon in the presence of a mixture of cuprous chloride and aluminium chloride which acts as a catalyst (Gattermann - Koch reaction). The mixture of gases probably reacts as the equivalent of the unisolated acid chloride of formic acid (formyl chloride) ... 

FUELS, SYNTHETIC - LIQUID FUELS] (Vol 12) Gattermann-Koch reaction... 

In the presence of aluminum chloride and a small amount of cuprous haUde, a mixture of hydrogen chloride and carbon monoxide serves as a formyl a ting agent of aromatics (Gattermann-Koch reaction) (107) ... 

The Gattermann-Koch reaction when appHed to alkenes or alkanes gives ketones or acids but not aldehydes. However, the Vilsmeier aldehyde synthesis can be appHed to aUphatic compounds. For example, 1,2-diaLkoxyethylenes react with /V-methy1foTmani1ide and POCl to give alkoxymalondialdehydes ... 

When aqueous solutions of aromatic and heteroaromatic diazonium salts are treated with cuprous chloride, -bromide, or -cyanide, the corresponding aromatic chlorides, bromides, or cyanides are formed, respectively. In many cases the anions mentioned must be present in excess. This reaction, the Sandmeyer reaction, was discovered by Sandmeyer in 1884. A variant carried out with copper powder and HBr or HC1 was for many years called the Gattermann reaction (Gattermann, 1890). As it is often confused with the Gattermann-Koch reaction (ArH + CO + HC1 ArCHO), and as it is mechanistically not significantly different from Sandmeyer s procedure, the name Gattermann reaction should be avoided. 

Gattermann-Koch reaction 230 Gattermann reaction 230 General acid/base catalysis, see Bronsted catalysis... 

Gabriel synthesis Gattermann aldehyde reaction Gattermann reaction Gattermann-Koch reaction Gomberg-Hey reaction Grignard reaction... 

Formylation may be carried out by use of CO, HC1, and A1C13 (the Gattermann-Koch reaction) it is doubtful whether HCOC1 is... 

Gattermann aldehyde synthesis, 9, 2 Gattermann-Koch reaction, 5, 6 Germanes, addition to alkenes and alkynes, 13, 4 Glycals,... 

When rearrangements occur in these systems, the products obtained will often be thermodynamically rather than kinetically determined (62). In some instances—e.g., the Gattermann-Koch reaction—the stability of the complex produced is responsible for the fact that the reaction can be carried out at all (4, 9). 

Adams modification of, 690, 701,702 Gattermann reaction, 593, 606 Gattermann-Koch, reaction 689, 697, 698... 

The Gattermann synthesis is somewhat less selective than the Gattermann-Koch reaction. In the HCN—HC1—A1C13 system, the substrate selectivity is 49.1, with 56.4% of para-isomer formation, whereas the corresponding values for the Zn(CN)2—HC1—A1C13 system in nitromethane solvent are 128 and 63.9%, respectively.90... 

GATTERMANN-KOCH REACTION. Formulation of hen/cne, alkyl-betuenes. or polycyclic aromatic hydrocarbons with carbon monoxide and hydrochloric acid in the presence of aluminum chloride al high pressure. Addition of cuprous chloride allows Ihe reaction to proceed at atmospheric pressure. 

Crafts alkylation and acylation (Section 22-4E and 22-4F), the Gattermann-Koch reaction for preparation of aldehydes from arenes and carbon monoxide (Section 22-4F), and the Kolbe-Schmitt, Reimer-Tiemann, and Gattermann reactions for synthesis of acids and aldehydes from arenols (Section 26-1E). 

Among the most frequently used formylation methods, the Gattermann-Koch reaction shows the highest selectivity reflected both in the observed high toluene- benzene rate ratios as well as a high degree of para substitution (Table 5.30). 

The Gattermann-Koch reaction, in which carbon monoxide and hydrogen chloride are bubbled through a solution containing benzene and aluminium chloride, is a further example of direct formylation (Scheme 6.5). The formyl cation, HC=0, is thought to be the attacking electrophile, though it is probably complexed to Al. 

Gabriel reaction, 679 Gattermann-Koch reaction, 280 Gattermann reaction, 94, 280 Glycerides, preparation, 481, 482 Glycidamides, preparation, 570 Glycidic acids, decarboxylation, 295 pyrolysis, 348... 

It may be synthesized by the Reimer-Tiemann or Gattermann-Koch reactions from pyrocatechinol, 1-2-di-hydroxy benzene. 

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