Remote aromatic stabilization in radical reactions

The rates of free radical reduction of a series of anthracene derivatives and 1-phenyl-4-bromodecane with tributyltin hydride are mediated by the remote aromatic substituent in an apparent through-space interaction. Density functional calculations suggest that this enhancement is not due to direct stabilization of the free radical intermediate, and is likely to be achieved through the interaction of the aromatic moiety with the polarized transition state leading to the intermediate.