Trans-Silylation – A New Method for the Synthesis of Silylated Phosphorus Ylides

✍ Scribed by Prof. Dr. H. Schmidbaur; Dipl.-Chem. W. Malisch

• Publisher: John Wiley and Sons
• Year: 1970
• Tongue: English
• Weight: 217 KB
• Volume: 9
• Category: Article
• ISSN: 0044-8249
• DOI: 10.1002/anie.197000771

✦ Synopsis

of Groups IVb and Vb as tridentate ligands to transition metal carbonyls have hitherto failed. We have now been able to prepare the first representative of this class of compounds, nonaphenylcyclotrisiIaphosphanetricarbonyln~olybdenum(0) ( I ) , by reaction of nonaphenylcyclotrisilaphosphane 131 with cycloheptatrienetricarbonylmolybdenum.

co OC\ /co

Compound ( I ) can be prepared in yields of up to 52% as brilIiant yellow crystaIs which are readily soluble in tetrahydrofuran and hot benzene, are sensitive to air, and decompose slowly with charring at temperatures above 165 "C.

The IR spectrum [41 shows two sharp v C 0 bands at 1931 and 1838 cm-1 and three vSiP bands at 393, 333, and 305 cm-1, corresponding to a molybdenum complex having an octahedral structure (C3") with silylphosphine in the chair configuration as tridentate ligand. A complete elemental analysis and cryoscopically determined molecular weight were also in agreement with such a structure. Attempts to prepare analogous germyl-and stannyl-tricarbonylmolybdenum complexes as well as the corresponding chromium and tungsten compounds resulted in the formation of complex mixtures only.