Reactions of an Isolable Dialkylstannylene with Carbon Disulfide and Related Heterocumulenes

The reaction of isolable
dialkylstannylene 1 with
an excess amount of CS2 produces an isomeric mixture of
3,3′-distanna-2,2′,4,4′-tetra­thia­bicyclo­butylidene 8 and 3,7-distanna-2,4,6,8-tetra­thia­bicyclo­[3.3.0]­oct-1(5)-ene 9 with a ratio depending on the reaction conditions. Compounds 8 and 9 are separated by column chromatography
and characterized by NMR spectroscopy and X-ray crystallography. Detailed
investigation of the reaction has revealed that the initial product
is 8, which isomerizes to 9 irreversibly
under the catalytic influence of 1 as a Lewis acid. The
above view is supported by the theoretical DFT calculations. Treatment
of 1 with ArNCO [Ar = 2,6-iPr2C6H3] affords the corresponding
carbamoyl­(hydroxyl)­stannane 11 via the hydrolysis
of the corresponding sila­aziridinone formed by the [1 + 2] cycloaddition
reaction of 1 with the NC double bond of the
isocyanate. Stannylene 1 reacts with ArNCS,
giving a mixture of complex products, while 1 does not
react with CO2.

将可分离的二甲基锡烯1与过量的二硫化碳反应，可得到3,3'-二取代-2,2',4,4'-四硫杂双环丁基乙烯8和3,7-二取代-2,4,6,8-四硫杂双环[3.3.0]辛-1(5)-烯9的异构体混合物，其比例取决于反应条件。化合物8和9通过柱色谱分离，并通过核磁共振波谱学和X射线晶体学进行表征。对反应的详细研究揭示了初始产物为8，在1作为路易斯酸的催化作用下不可逆地异构化为9。上述观点得到了理论DFT计算的支持。将1与ArN≡C=O [Ar = 2,6-iPr2C6H3]处理，通过由1与异氰酸N≡C双键的[1+2]环加成反应形成的相应硅氮杂环已酮的水解，得到相应的羰基（羟基）锡烷11。锡烯1与ArN≡CS反应，产生复杂的产物混合物，而1不与二氧化碳反应。