Alkyltin chlorides reactions

Alkyltin Intermedia.tes, For the most part, organotin stabilizers are produced commercially from the respective alkyl tin chloride intermediates. There are several processes used to manufacture these intermediates. The desired ratio of monoalkyl tin trichloride to dialkyltin dichloride is generally achieved by a redistribution reaction involving a second-step reaction with stannic chloride (tin(IV) chloride). By far, the most easily synthesized alkyltin chloride intermediates are the methyltin chlorides because methyl chloride reacts directiy with tin metal in the presence of a catalyst to form dimethyl tin dichloride cleanly in high yields (21). Coaddition of stannic chloride to the reactor leads directiy to almost any desired mixture of mono- and dimethyl tin chloride intermediates ... 

The other commercially important routes to alkyltin chloride intermediates utilize an indirect method having a tetraalkjitin intermediate. Tetraalkyltins are made by transmetaHation of stannic chloride with a metal alkyl where the metal is typicaHy magnesium or aluminum. Subsequent redistribution reactions with additional stannic chloride yield the desired mixture of monoalkyl tin trichloride and dialkyltin dichloride. Both / -butjitin and / -octjitin intermediates are manufactured by one of these schemes. 

Mercaptides are unchallenged as the ligand of choice for the other entities bonded to the tin, but carboxylates can also be used. Whereas a variety of mercaptans are used, the thioglycolic acid derivatives remain the laigest single mercaptan. Dibutyltin bis(isooctyl thioglycolate) [25168-24-5] and butyltin tris(isooctyl thioglycolate) [25852-704] are two common examples. These materials are produced by the reaction of the appropriate alkyltin chloride or oxide, and the mercaptan. 

SnCU is also the principal source of alkyltin chlorides, R SnCl4 [51]. Allyltrialkyl-tin reagents react with SnCU to produce allyltrichlorotin species through an Se2 pathway (Eq. 32) [52-56], Allyltrimethylsilanes react with SnCU to produce the corresponding allyltrichlorotin (Eq. 33) [57]. Silyl enol ethers react with SnCU to give a-tri-chlorotin ketones (Eq. 34) [58]. Transmetalation or metathesis reactions of this type... 

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. 

Trialkylstannylalkyl)phosphonates, R3SnCHR P(0)(0R")2> can be prepared by lithia-tion of the alkylphosphonate followed by reaction with the alkyltin chloride (equation 6-20),56 or by an Arbuzov reaction between an iodomethyltin compound and a phosphite (equation 6-21).57 The activated Sn-C bond will then add to a dipolar double bond, and the phosphonate group can be reduced to CH2PH2 with lithium aluminium hydride. 

The stoichiometric reactions of alkyltin chlorides with sodium alkoxides generally yield the aUcyltin alkoxide derivatives. The method was finally extended to the preparation of Bu Sn(OR)3, in spite of earlier unsuccessful attempts ... 

The reactions of tetraorganotins with ICl, EBr, and CICN have been investigated as synthetic routes to aryl cyanides (111) and alkyltin bromides and chlorides (112,113). 

The opposite polarity in the organotin reagent R3Sn5+X5 can be exploited in, for example, the reaction of a tin alkoxide with an vinyl ester,83 the addition of an alkoxy- or amino-tin compound to a ketene,84 the reaction of a silyl enolate with a tin chloride,85 or the addition of an alkyltin hydride under non-radical conditions to an a,P-unsaturated carbonyl compound.86... 

Further reaction of the organotin(II) chloride 14 with 4-tolyl-, neopen-tyl-, or neophyllithium affords the unique corresponding mixed aryl—alkyltin(II) compounds 15,16, and 17 respectively [Eq. (3)] (85). 

The reaction between powdered tin, hydrogen chloride, and an Q ,/i-unsaturated carbonyl or cyano compound produces diorganotin dichloride species (equation 3). Tin(II) halides react similarly to give X3SnCH2CH2Y (equation 4). Direct reactions of tin (II) halides with alkyl halides to give alkyltin trihalides require the same catalysts as used for tin/alkyl halide reactions trialkylstibines are particularly effective catalysts (equation 5). 

Reactions of tetra-alkyltin compounds with mercury(n) iodide in 96% methanol, as with mercury(n) chloride, - are bimolecular. The variation of rate constant with alkyl group suggests an open S 2 transition state (5). Further evidence for this mechanism is provided by the variation of rate constant with solvent Y values for the particular case of the tetraethyltin compound reacting with mercury(n) chloride in a range of aqueous methanol mixtures. Solvent effects in this last series of reactions have been separated into initial state and transition state contributions by the determination of heats of solution and of transfer of the reactants. The effect of added lithium perchlorate on reaction rates for tetra-alkyltin compounds with mercury(ii) iodide again indicates bimolecular electrophilic... 

The separation of solvent effects on reactivities into constituent initial-state and transition-state effects by the use of appropriate kinetic and thermodynamic data has been successfully carried out for several organic reactions. Thus, for example, the solvolysis of t-butyl chloride and the Menschutkin reaction were treated in this manner some time ago a recent organic example is afforded by the solvolysis of isopropyl bromide in aqueous ethanol. For inorganic reactions, this approach was early used for reactions of tetra-alkyltin(iv) compounds with mercury(ii) halides. A more recent analysis of reactions of low-spin iron(n) complexes with hydroxide and with cyanide in binary aqueous mixtures was complicated by the need to make assumptions about single-ion values in such ion+ion reactions. Recent estimates of thermodynamic parameters for solvation of complexes of the [Fe(phen)3] + type are helpful in this connection. However, it is more satisfactory to work with uncharged reactants when trying to undertake this type of analysis of reactivity trends. A suitable system is provided by the reaction of [PtClaCbipy)] with thiourea. In dioxan-and tetrahydrofuran-water solvent mixtures, reactivity is controlled almost entirely... 

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