Preparation of half-sandwich diazoalkane complexes of osmium

Diazoalkane complexes [OsCl(η6-p-cymene)(N2CAr1Ar2){PPh(OEt)2}]BPh4 (1, 2) [Ar1 = Ar2 = Ph; Ar1 = Ph, Ar2 = p-tolyl; Ar1 = H, Ar2 = COOEt] were prepared by allowing compounds OsCl2(η6-p-cymene)[PPh(OEt)2] to react with diazoalkane in ethanol. Diazo-pyridine derivatives [OsCl(η6-p-cymene){κ1-(4-C5H4N)(Ph)CN2}L]BPh4 (3, 4) [L = PPh(OEt)2, P(OEt)3] were also prepared by reacting chloro-compounds OsCl2(η6-p-cymene)L with 4-[diazo(phenyl)methyl]pyridine, (4-C5H4N)PhCN2, in ethanol. Treatment of diazoalkane complexes 1 and 2 with CH2CH2 (1 atm) and PhCCH in ethanol led to ethylene [OsCl(η2-CH2CH2)(η6-p-cymene){PPh(OEt)2}]BPh4 (5) and carbene [OsCl{C(CH2Ph)(OEt)}(η6-p-cymene){PPh(OEt)2}]BPh4 (6) derivatives.

The synthesis of diazoalkane complexes and κ1-pyridine-diazo derivatives of osmium is described.Figure optionsDownload as PowerPoint slide