Abstract
[50726-31-3] C6H3BrO4W (MW 402.84) InChI = 1S/C2H3.4CO.BrH.W/c5*1-2;;/h1H3;;;;;1H;/q;;;;;;+1/p-1 InChIKey = UZNITRMSTQBNAH-UHFFFAOYSA-M (couples with alkynes1) Alternate Name: trans-bromotetracarbonyl(methylmethylidyne)tungsten. Physical Data: solid at 25 °C; mp dec; yellow crystals. Solubility: sol pentane, THF, Et2O. Form Supplied in: not commercially available. Preparative Methods: prepared from the reaction of pentacarbonyl(1-methoxyethylidene)tungsten and Boron Tribromide2 or tetramethylammonium acetyl(pentacarbonyl)tungstate and Oxalyl Bromide.3 Purification: after synthesis, trans-bromotetracarbonyl(ethylidyne)tungsten is purified by chromatography on silica gel at −30 °C using 1∶1 pentane–dichloromethane as an eluent, followed by recrystallization from pentane at −78 °C. Purification by extensive washing with pentane at low temperature is apparently sufficient for use in alkyne coupling reactions.1 Handling, Storage, and Precautions: unstable above 35 °C; decomposes in air.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
