Organotin Pseudohalides

This chapter comprises organotin compounds having a pseudohalogen group linked to tin. Aside from (iso)cyanides, (iso)cyanates (iso)thiocyanates and azides reported in the Main Volume, a number of novel derivatives are added. These include (iso)selenocyanate-NCSe, fulminate-CN 0 and N-derivatives of dicyanamide-N(CN)2 and tricyanomethane-N C C(CN)2 The compounds listed in Tables 158 and 159 are prepared by the following methods. 

Reactions with organotin oxides, hydroxides and alkoxides  

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Spectra of organotin pseudohalides are analysed and the structure of Me2Sn(NCS)2.2H2O.18-crown-6 shown to involve trans-substitution with H2O H-bonding to the ether. Me SnCl and K3Co(CN)g form... 

Organotin pseudohalides containing tin-oxygen bonds are only quite recently known. Several of the new derivatives may contain a four-membered stannoxane -ring, cf. the structural formula in the Main Volume, page 33 The following scheme gives synthetic methods for the compounds summarized in Tables l60 and l6l. 

Covalent Organotin Halide, Pseudohalide, Carboxylate, and Nitrate Complexes... 

Melvyn R. Churchill and Ronald Mason Structural Aspects of Organotin Compounds Rokuro Okawara and Masanori Wada Organometallic Pseudohalides... 

Organotin hydrides are advantageous as reductants in terms of their facile availability, stability, and reactivity. - Almost all tin hydrides are liquids, and stoichiometric tin-hydrogen bonds can be used. In general, the tin hydride reductions have been performed under radical conditions using initiators such as azobisisobutyroni-trile (AIBN), triethylborane, and UV irradiation. The reduction of organic halides and pseudohalides by tri- -... 

Organotin halides can be converted to the corresponding pseudohalides on treatment with suitable metal salts (Scheme 10). Tin oxides or hydroxides have been used with NH4Y, HY, or MesSiY and tin auudes have been used with HY (Y = SON (or NCS), NCO, N3, CN, etc.)... 

Sequences of acceptor strengths of organotin hahdes and pseudohalides for RsSnX are X = NCS > Cl > Br > I andforR SnX4 are RSnXs > R2S11X2 > RsSnX. Stronger complexes are found for O and N ligands than for S and P ligands. 

Hexamethyl- and Hexabutylditin. These ditins undergo cross-coupling with a variety of organohalides and pseudohalides (such as aryl halides, vinyl triflates, acyl chlorides, and allyl halides) in this protocol to give the correponding tin compounds. The reaction is particularly useful for preparation of organotins with labile functionalities that are not compatible with other procedures. 

Few simple tin pseudohalides are known, but there is an extensive chemistry of organotin pseudohalides229, in which the synthesis and properties of the tin-pseudohalogen bonds have been studied. 

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