Thiolactim ethers

Gompper [83AG(E)717] has prepared the thiolactim ethers (172) by the action of Meerwein s reagent on the thiolactam. 

The N —> Ge (2.054 A) and Ge—Cl (2.566 A) distances in thiolactim ether 156a are the shortest and the longest, respectively, among the values known for pentacoordinated germanium derivatives. Moreover, the Ge atom is displaced from the equatorial plane toward the N atom (AGe = —0.05 A) i.e. the Ge—Cl bond represents an additional bond. 

Comparison of structural characteristics of the thiolactim ethers 156a and the Si analogue, Si-156a (Table 36), shows that the strength of the intramolecular N M (M = Si, Ge) interaction is approximately the same in the coordinative N MCg —Cl units. The relative lengthening of the N—M bond in these compounds relative to the normal bond length in the corresponding tetrahedral compounds, as well as ASi, AGe and the N—M bond order is actually equal . 

Secondary thioamides react with dimethylcyanomethyl radicals to give thioimidic acid anhydrides (288 Scheme 44), in poor yields,whereas with phenyl radicals phenylthioimidates (289) are obtained in fairly good yields. Thiolactim ethers (290 equation 154) (ring size 6-9) have been prepared by rearrangement of l-azido-l-methylmercaptocycloalkanes. ... 

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