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Reduction of 1-t-butyl-1,2,3,4,5-pentaphenylstannole by lithium gave the stannole dianion. Reduction of the bi(1,1-stannole) having a t-butyl group on the tin by lithium also gave the stannole dianion, the formation of which was evidenced by spectral analysis and chemical trapping reaction.

Reactions of Ph3SnCl and RSnCl3 (R = Me, n-Bu) with R4 N+Cl− and disodium maleonitriledithiolate, Na2(mnt), yield the monostannole [((CN)2C2S2)SnPh3][Me4N] (1) and the new distannoles [((CN)2C2S2)2,SnR][Et4N] [R = Me (2), n-Bu (3)]. X-ray analysis reveals the geometries of 1 as trigonal bipyramidal and 2 and 3 as square pyramidal. The tristannole [((CN)2C2S2)3Sn][Et4N][Na] (4) results from Sn-C bond cleavage of PhSnCl3 in a hydrolysis reaction with Na2(mnt) and Et4N+ Cl−. The geometrical data on organotin complexes containing ring unsaturation, 1-3, and related anionic five-coordinated tin compounds show that the distortion coordinate expressing solid-state nonrigidity is the Berry pseudorotational coordinate. As a result of this work, one is able for the first time to compare structural principles for five-coordinated compounds established for other main-group 14 and 15 elements. Their significance in reaction mechanisms is discussed. Stannole 1 crystallizes in the monoclinic space group Cc with...

Bis(trimethylstannylethynyl)phenylphosphane (1) reacts regio- and stereoselectively via 1,1-organo-boration with one equivalent of triethylborane (4a) or triisopropylborane (4b) to give the (Z)-alkene derivatives 5a and 5b, respectively, in quantitative yield. With an excess of 4a the bis(alkenyl)phosphane 6a is formed ((Z)-configuration of both alkenyl groups). The reaction between bis(dimethylphos-phanylethynyl)dimethyltin (2) and 4a leads to a complex reaction mixture, whereas bis(diphenylphos-phanylethynyl)dimethyltin (3) reacts with 4a to give selectively the organometallic substituted stannole derivative 8a. In this case, a zwitterionic intermediate (9a) was identified by 1H-, 11B-, 13C-, 31P and 119Sn NMR. In 9a a positively charged triorganotin fragment is stabilized by intramolecular π-coordination to the C[tbnd]C bond of an alkynylborate group. The reaction between 3 and 4b affords a mixture (12:1) of the stannole derivative 8b and the 1-stanna-4-bora-2,5-cyclohexadiene derivative 10b. ...

1,4-Dichlorobuta-1,3-diene has been lithiated and reacted with organosilyl and tin chlorides. Only polymerized starting material, rather than the hoped for parent sila- and stannacyclopentadienyl (silole and stannole) ring systems result from the action of the 1ithiated material on diorganodichlorosilanes and diorganotin di-chlorides. Addition of the 1ithiated butadiene to trimethylchloro-silane and trimethyltin chloride yields products resulting from dehydrochlorination and multiple bond migration in the starting dichlorobutadiene.