Diorganotin dichloride

Prepa.ra.tlon, Diorganotin dichlorides are the usual precursors for all other diorganotin compounds three primary methods of manufacture are practiced. Dibutyltin dichloride is manufactured by Kocheshkov redistribution from cmde tetrabutyltin and stannic chloride and usually is cataly2ed with a few tenths of a percent aluminum trichloride ... 

Diorganotin dichlorides, in diorganotin preparation, 24 820 Diorganotin dihalides, 24 820 Diorganotin esters, 24 820 Diorganotin mercaptocarboxylates, as polyurethane foam catalysts,... 

Cyclostannanes (R2Sn) are obtained, primarily as the hexamer (n = 6), by treatment of the diorganotin dichloride R2SnCl2 with sodium naphthalenide [eqn (2.4)]. ... 

The synthetic procedures are general giving products using organotin trichlorides, diorganotin dichlorides, triorganotin chlorides and tin II and tin IV. Sample results appear in Table 2. The molar ratio of tin-containing reactant was based on the assumption that all of the active sites of the reactants would be reacted. 

The triorganotin chloride adducts readily exchange with base or with other adducts. The diorganotin dichlorides form only 1 1 adducts with tributylphosphine, even at high base to acid ratios. The lower dialkyltin dichlorides prefer to form 1 1 adducts (at 1 1 mole ratios) with tributylphosphine rather than tributylphosphine oxide (TBPO), whereas... 

To date, the synthesis of strained [l]stannafeiTocenophanes as precursors for ROP is restricted to compounds with bulky substituents at tin. Previous attempts to prepare tin-bridged ferrocenophanes by the reaction of dilithioferrocene with diorganotin dichlorides, R2SnCl2, containing less bulky substituents (R = Me, Et, w-Bu, Ph) resulted in the isolation of oligomers (Mn < 4.6 x 10 ) and cyclic dimers . The crystal structure analyses of the [2]distannaferrocenophane 60 and the [3]tristannaferrocenophane 61, which are essentially unstrained, were also reported " . 

The reaction between powdered tin, hydrogen chloride, and an a,/3-nnsatnrated 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 aUcyltin trihalides require the same catalysts as used for tin/alkyl halide reactions trialkylstibines are particularly effective catalysts (equation 5). 

Finally, the disproportionation reaction of the triorganotin chloride 70 into the novel diorganotin dichloride 113 has been reported. On the basis of its H and 13C NMR spectra, an octahedral coordination geometry has been proposed, schematically shown in Eq. (19)... 

Additional evidence for such an intermediate was obtained from H NMR studies of a mixture of the diorganotin dichloride, 117, and the diorganotin dibromide, 118. The H NMR spectrum of a mixture of 117 and 118 in toluene-pure compounds, 0.80 and 1.00 ppm, respectively. Below — 80 °C, the... 

The hydrolysis of the non-symmetrically substituted diorganotin dichloride (Me3SiCH2)PhSnCl2 gives rise to formation of the tetraorganodistannoxane [(RPh(Cl)SnOSn(Cl)PhR]2 (8, R=Me3SiCH2), which in solution is kinetically labile on the laboratory timescale, but inert on the Sn NMR timescale. Thus, in solution, all five possible isomers of 8 are detected (Scheme 2.10.4). 

In one case a discrete polymer, dodecamethylcyclohexatin, has been obtained 211) from the reaction of dimethyltin dichloride with sodium in liquid ammonia. Using diorganotin dichlorides and sodium in xylene, a,co-dichloropolytin compounds may be obtained in yields of up to 50% 212). One major product was obtained from each tin halide dimethyltin dichloride produced a ditin diethyl-, dipropyl-, and dibutyltin dichloride gave tetratin, tritin, and pentatin, respectively 212). 

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