Indirect electrochemical cyclization of bromoalkoxylated derivatives mediated by nickel(II) complex in environmental-friendly medium

• DOI: 10.1016/j.electacta.2008.01.024
• Publication Date: 2008-01-21T12:31:31Z
• Authors: E. Duñach; M.J. Medeiros
• Keywords: Ethanol solvent; Electroreduction; Science & Technology; Cyclization; Nickel(II) complex; Heterocycles; 01 natural sciences; 0104 chemical sciences

Abstract 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.