Heteroallene Insertions into Tin(II) Alkoxide Bonds.

A series of iso-carbamate complexes have been synthesized by the reaction of [Sn(OPr)] or [Sn(OBu)] with either aryl or alkyl isocyanates, ONC-R (R = 2,4,6-trimethylphenyl (Mes), 2,6-diisopropylphenyl (Dipp), isopropyl (Pr), cyclohexyl (Cy) and -butyl (Bu)). In the case of aryl isocyanates, mono-insertion occurs to form structurally characterized complexes [Sn{κ--R-NC(OPr)O}(μ-OPr)] (: R = Mes, : R = Dipp) and [Sn{κ--R-NC(OBu)O}(μ-OBu)] (: R = Mes, : R = Dipp). The complicated solution-state chemistry of these species has been explored using H DOSY experiments.