Alkali metal derivatives of sulfinimidamides. Preparation and crystal structures

Article abstract of DOI:10.1016/0022-328X(91)86360-3

A series of compounds has been prepared in which the NH proton of the sulfiniminamines Me3SiN=S(R)-NMR' (R=Ph (mainly) or ^tBu, R'=^tBu or SiMe3) is replaced by Li, Na, K, Rb, or Cs.The compounds form a series of reagents of increasing reactivity which could be used, for example, to introduce chelating ligands into transition metal complexes.The structures of the compounds have been determined by X-ray diffraction.When there is a phenyl substituent on the sulfur atom, the metal derivatives are isomorphic dimers, involving three fused four-membered rings in a step-shaped structure.The higher the atomic number of the metal, the stronger is the η-coordination of the phenyl group to the metal.With a t-butyl group on the sulfur atom the structures of the lithium derivatives <(Me3SiN=S(^tBu)-NR')Li>2 are different for R'=SiMe3 and ^tBu.For the former the step-shaped structure is still present, but the latter forms an eight-membered ring.Although these ^tBu derivatives are synthesized in diethyl ether, their lithium atoms are not coordinated by donor molecules, in contrast to those in the phenyl-substituted species.