Kocheshkov reaction

Of this research, I will mention here only aminoferrocene. We were very glad to obtain the compound through the Kocheshkov reaction of ferrocenyllithium and hydroxylamine 0-ether [Nesmeyanov, Perevalova, Shilovtseva 260)] later, we synthesized aminoferrocene via other paths 261, 262). 

Scheme 1-1 Organotin synthesis based on die Grignard and Kocheshkov reactions.

The metal M is commonly magnesium in a Grignard reagent, or lithium, or aluminium, and X is commonly halide. Selective partial alkylation of the tin is usually difficult to achieve, and the reaction is taken to completion to give R4Sn (equation 4-8) if any organotin halides are present, they can be removed as the complexes which they form with dry ammonia, or as the insoluble fluorides which they form with sodium fluoride. Any subsequent dealkylation, if required, can then be achieved by the Kocheshkov reaction (Section 11.1.2). 

Reactions of organotin compounds with Lewis acids by have been carried out particularly with mercury(II) salts in mechanistic studies, with SnCl4 (the Kocheshkov reaction) for the preparation of alkyltin chlorides, and with lead tetraacetate. 

The Kocheshkov reactions are discussed in Section 11.1.2 on organotin halides. 

Allyltin halides are formed by the Kocheshkov reaction, and have also been obtained by the retro-ene elimination of a ketone from a homoallyloxystannane.24... 

Erotic reagents (e.g. equation 9-49) and other electrophiles (e.g. halogens) readily cleave the Cp-Sn bond, and the Kocheshkov reaction with SnCL occurs rapidly even at... 

The low reactivity of the cyclohexyl-tin bond has been exploited in preparing the spacer bridged bistrichlorides, Cl3SnSpSnCl3 (Sp = alkylene, arylene, or aryl-dimethylene) by the Kocheshkov reaction of Cy3SnSpSnCy3 with S11CL4.12 From these hexachlorides, a variety of compounds R3SnSpSnR3 (e.g. R = MeOC) can be prepared. 

Some examples of the Kocheshkov reaction are given in Table 11-1. 

Table 11-1 Organotin halides prepared by the Kocheshkov reaction.

Chemical Properties. The most impoitant reactions which tetraorganotins undergo are heterolytic, ie, electrophilic and nucleophilic, cleavage and Kocheshkov redistribution (81—84). The tin—carbon bond in tetraorganotins is easily cleaved by halogens, hydrogen hahdes, and mineral acids ... 

The most widely utilized reaction of tetraorganotins is the Kocheshkov redistribution reaction, by which the tri-, di-, and in some cases the monoorganotin hahdes can be readily prepared ... 

The production of triphenyl tin hydroxide [76-87-9] and triphenyl tin acetate [900-95-8] start with triphenyl tin chloride, which is prepared by the Kocheshkov redistribution reaction from tetraphenyltin and tin tetrachloride. The hydroxide is prepared from the chloride by hydrolysis with aqueous sodium hydroxide. The acetate can be made directiy from the chloride using sodium acetate or from the hydroxide by neutrali2ation with a stoichiometric quantity of acetic acid. 

Allyltin chlorides, allylSnIL/T-, are more reactive in carbonyl addition than are the allyltrialkylstannanes, allylSnRj, and for this purpose, the latter can be converted into the former by the Kocheshkov redistribution reaction with BuSnCl3 or S11CI4 the /ra r-stannylation can be carried out with the carbonyl compound in situ in a one-pot process (Equation (97)).270... 

Organotin halides are commonly prepared by the Kocheshkov redistribution reaction, where an organic group on tin (e.g., in SnR4) exchanges (reversibly) with a halide group on tin (e.g., in SnCLt).64 Two recent examples are shown in Equations (125) and (126). The first reaction exploits the high reactivity of the Sn-Me bonds, and the second... 

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