Indirect electrochemical cyclization of bromoalkoxylated derivatives mediated b...

• Author(s): Duñach, E. ; Medeiros, Maria José
• Date: 2008
• Persistent ID: http://hdl.handle.net/1822/26809
• Origin: RepositóriUM - Universidade do Minho
• Subject(s): Ethanol solvent; Cyclization; Nickel(II) complex; Electroreduction; Heterocycles
• Document Type: Article
• Language: English

Description

An improved procedure has been developed using a catalytic amount of a nickel(II) complex in the efficient and selective electrochemical cyclization of propargyloxy and allyloxy bromo derivatives into substituted tetrahydrofurans using ethanol and ethanol–water mixtures as environmental-friendly systems. The reduction of the substrates proceeded via one-electron cleavage of the carbon–bromine bond to form a radical-type intermediate that undergoes cyclization to afford the tetrahydrofuran structures in good yields.