[16800-47-8] · C9H9N3O3W · Tris(acetonitrile)tricarbonyltungsten · (MW 391.06)
(catalyst for nucleophilic substitution of allylic acetates1)
Physical Data: mp 135 °C (dec).
Solubility: sol acetonitrile, nitromethane.
Form Supplied in: not commercially available.
Preparative Methods: by refluxing Hexacarbonyltungsten in Acetonitrile in an inert atmosphere. Removal of solvent under an inert atmosphere yields tris(acetonitrile)tricarbonyltungsten.2 Solutions of the reagent can be prepared by photolysis of hexacarbonyltungsten in acetonitrile.
Purification: can be purified by recrystallization from acetone-hexane.3 The crude solid or solution obtained in the above preparations is typically used without further purification.
Handling, Storage, and Precautions: air and thermally sensitive; pyrophoric. Use in a fume hood.
Treatment of allylic acetates or carbonates with various carbon nucleophiles in the presence of tris(acetonitrile)tricarbonyltungsten and bipyridyl leads to the allylic alkylation product (eqs 1 and 2).1 Suitable nucleophiles include those derived from carbon acids having a pK
James W. Herndon
University of Maryland, College Park, MD, USA