In the Gatterman reaction

In a variation of the Gatterman reaction an alkyl cyanide RCN is used in place of HCN as a useful way of preparing ketones from reactive aromatic species that do not react well under Friedel-Crafts conditions. The electrophile involved is effectively R—C NH+, although, perhaps, the imino chloride, R(C NH)C1, the analogue of an acyl chloride, RCOCl, is also involved. As in the Gatterman reaction, the imine is an intermediate. 

Formylation with Zn(CN)2 and HCI is called the Gatterman reaction It can be applied to alkylbenzenes, phenols and their ethers, and many heterocyclic compounds. However, it cannot be applied to aromatic amines. In the original version of this reaction, the substrate was treated with HCN, HCI, and ZnCl2, but the use of Zn(CN)2 and HCI (HCN and ZnCF are generated in situ) makes the reaction more... 

Treatment of diazonium salts with cuprous chloride or bromide leads to aryl chlorides or bromides, respectively. In either case the reaction is called the Sandmeyer reaction The reaction can also be carried out with copper and HBr or HCl, in which case it is called the Gatterman reaction (not to be confused with 11-16). The Sandmeyer reaction is not useful for the preparation of fluorides or iodides, but for bromides and chlorides it is of wide scope and is probably the best way of introducing bromine or chlorine into an aromatic ring. The yields are usually high. 

Many nitriles have been used. Even aryl nitriles give good yields if they are first treated with HC1 and ZnCl2 and then the substrate added at 0°C.357 In fact, this procedure increases yields with any nitrile. If thiocyanates RSCN are used, thiol esters ArCOSR can be obtained. The Gatterman reaction (1-16) is a special case of the Hoesch synthesis. 

In the Gatterman-Koch reaction, a formyl group (-CHO) is introduced directly onin a benzene ring. For example, reaction of toluene with CO and HCI in the presenc of mixed CuCl/AlClg gives p-metbylbenzaldehyde. Propose a mechanism. 

The Cu(I)/Cu(II) couple is utilised in the Sandmeyer reaction, in which an aromatic diazonium salt is converted into the corresponding aryl chloride by the catalytic action of Cu(I)Cl. There is a variation that uses copper and HC1, which is called the Gatterman reaction. 

C6H5N2 + Cl- C HjCl + N2 This reaction was discovered by the German chemist Traugott Sandmeyer (1854-1922) in 1884. A variation of the reaction, in which the catalyst is freshly precipitated copper powder, was reported in 1890 by the German chemist Ludwig Gatterman (1860-1920). This is known as the Gatterman reaction (or Gat-terman-Sandmeyer reaction). 

In this new strategy, methyl 3,5-dihydroxybenzoate was subjected to the Gatterman reaction and the resulting product was transformed by chloro-methylation into 90 (Scheme 17), which was found to be different from the phthalide prepared earlier and therefore suggested that the correct structure for the previously prepared phthalide was 89. 

When unsubstituted, C-5 reacts with electrophilic reagents. Thus phosphorus pentachloride chlorinates the ring (36, 235). A hydroxy group in the 2-position activates the ring towards this reaction. 4-Methylthiazole does not react with bromine in chloroform (201, 236), whereas under the same conditions the 2-hydroxy analog reacts (55. 237-239. 557). Activation of C-5 works also for sulfonation (201. 236), nitration (201. 236. 237), Friede 1-Crafts reactions (201, 236, 237, 240-242), and acylation (243). However, iodination fails (201. 236). and the Gatterman or Reimer-Tieman reactions yield only small amounts of 4-methyl-5-carboxy-A-4-thiazoline-2-one. Recent kinetic investigations show that 2-thiazolones are nitrated via a free base mechanism. A 2-oxo substituent increases the rate of nitration at the 5-position by a factor of 9 log... 

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

Halo derivatives 127 have been obtained in moderate yields from the corresponding amines 126 via the Sandmeyer-Gatterman reaction (Equation 35) <1996CHEC-II(4)307>. 

In the early Gatterman s preparative chemistry book, " the one-pot synthesis of dUiydropyridine derivatives like those formed by the Hantzsch reaction was one of practical laboratory exercises. 

Alternatively, chlorine or bromine can also be introduced in the benzene ring by treating the diazonlum salt solution with corresponding halogen acid in the presence of copper powder. This Is referred as Gatterman reaction. 

A useful method for the synthesis of 5-chloro-l,2,4-thiadiazoles (206) is the reaction of amidines with trichloromethylsulfenyl chloride (see Equation (30)). 3-Halo derivatives (349) (X = Cl, Br, I) (Equation (57)) have been obtained in moderate yields from the corresponding amines (348) via the Sandmeyer-Gatterman reaction <84CHEC-I(6)463>. 3-Chloro-l,2,4-thiadiazolin-5-ones (350) and (351) can be prepared by reacting chlorocarbonylsulfenyl chloride with carbodiimides or cyanamides respectively (Scheme 79) <84CHEC-I(6)463>. 

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 ... 

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