Synthesis and structure of {{amino(triorganosilyl)carbene}pentacarbonyltungsten(0)} complexes and attempted synthesis of {[2-bis(trimethylsilyl)methyl-3-triorganosilyl-2H-azaphosphirene-κP]pentacarbonyltungsten(0)}

First examples of tungsten aminocarbene complexes [(OC5)W{C(SiR1nR23-n)NH2}] 2a–d (R1 = Ph, R2 = Me) were synthesized via ammonolysis of the corresponding methoxycarbene complexes 1a–d. They were characterized by NMR spectroscopy, MS, IR, UV/Vis and elemental analysis, and in the case of the C-triphenylsilyl derivative 2a by single-crystal X-ray structure analysis. The reaction of P-chloro alkylidenephosphane 3 with complexes 2a–d, meant to give 2H-azaphosphirene complexes, was monitored by 31P NMR spectroscopy to reveal the formation of the products 4–7, which were presumably formed via decomposition of the transient complexes 10a–d.

Synthesis and reactions of tungsten aminocarbene complexes [(OC5)W{C(SiRn1R3−n2)NH2}] I with a P-chloro alkylidenephosphane was studied hoping to obtain 2H-azaphosphirene complexes II.Figure optionsDownload as PowerPoint slideHighlights
► First examples of tungsten aminocarbene complexes bearing C-triorganosilyl groups were achieved via ammonolysis.
► A single-crystal X-ray structure analysis was obtained for the C-triphenylsilyl derivative.
► Reaction of a P-chloro alkylidenephosphane with these aminocarbene complexes didn’t lead to stable 2H-azaphosphirene complexes.
► Instead, formation of a cyclotriphosphane, a diphosphirane and bis(carbene) complexes was observed.