[12082-03-0] · C9H5ClCrO3 · Tricarbonyl(h6-chlorobenzene)chromium · (MW 248.59)
(phenyl cation equivalent1)
Alternate Name: (chlorobenzene)chromium tricarbonyl
Physical Data: mp 102-103 °C.
Solubility: sol THF, ether, benzene.
Form Supplied in: yellow crystals; not commercially available.
Preparative Method: prepared from the reaction of chlorobenzene with Hexacarbonylchromium in refluxing dioxane.2
Purification: recrystallized from ether/petroleum ether. Can also be purified by column chromatography on silica gel.
Handling, Storage, and Precautions: slightly air sensitive. Use in a fume hood.
Treatment of tricarbonyl(chlorobenzene)chromium (1) with various nucleophiles at 25 °C effects nucleophilic substitution of chlorine.1,3 Nucleophiles derived from carbon acids having a pK
Treatment of the title reagent with n-Butyllithium produces the lithiated arene complex (7), which is stable at low temperature. Treatment of complex (7) with electrophiles produces the ortho-substituted chlorobenzene derivatives (e.g. 8) (eq 3).5 At temperatures higher that -78 °C, complex (7) undergoes decomposition through a benzyne mechanism.6
James W. Herndon
University of Maryland, College Park, MA, USA