Boron trifluoride etherate


Boron trifluoride etherate, strictly boron trifluoride diethyl etherate, or boron trifluoride–ether complex, is the chemical compound with the formula BF3O2, often abbreviated BF3OEt2. It is a colorless liquid, although older samples can appear brown. The compound is used as a source of boron trifluoride in many chemical reactions that require a Lewis acid. The compound features tetrahedral boron coordinated to a diethylether ligand. Many analogues are known, including the methanol complex.

Reactions

It serves as a source of boron trifluoride via the equilibrium:
The BF3 binds to even weak Lewis bases, inducing reactions of the resulting adducts with nucleophiles.