BENZYLLITHIUM
BENZYLLITHIUM Basic information
- Product Name:
- BENZYLLITHIUM
- Synonyms:
-
- BENZYLLITHIUM
- LithiuM,(phenylMethyl)-
- CAS:
- 766-04-1
- MF:
- C7H7Li
- MW:
- 98.07
- Mol File:
- 766-04-1.mol
BENZYLLITHIUM Chemical Properties
- solubility
- sol ethers; DABCO complex crystallizes from hexane as it forms.
BENZYLLITHIUM Usage And Synthesis
Chemical Properties
By X-ray, the DABCO complex forms contact ion pairs with Li over planar benzyl anions and the THF-TMEDA complex has pyramidal benzylic carbon atoms. UV4 and 1H, 13C, and Li NMR studies have been reported.
Uses
Benzyllithium is a benzylating agent in substitutions and additions at carbon and used to attach benzyl groups to other metals and nonmetals.
Preparation
Preparative Methods of Benzyllithium: preparation from benzyl ethyl ether and Lithium in THF/ether is recommended on a large scale; toluene metalation for pure samples. Metalation of toluene with n-Butyllithium/TMEDA gives 90-91% yield, but contaminated with 5-6% m-tolyllithium and 2% each of o- and p-tolyllithium; metalation of toluene with butyllithium/Potassium t-Butoxide, then reaction of the red solid benzylpotassium with LiBr in ether, gives purer product. Preparations from organotin compounds by exchange may be contaminated with organotin compounds. A method involving treatment of benzyl selenides with BuLi at -78 °C should be especially useful for benzyllithiums containing halogens or methoxyls.
storage
Benzyllithium must be prepared and transferred under an inert gas to exclude oxygen and moisture.