2,4,6-tri-tert-butylphenyl and 2,4-di-tert-butyl-6-methylphenyl groups: Look similar, react differently

The crystal structures of molecules with two phosphaalkene groups have been determined. Differences in the stabilization of the P=C 7 pi-bond by the 2,4,6-tri-tert-butylphenyl and 2,4-di-tert-butyl-6-methylphenyl groups were observed. It has been found that lithium supermesityl(trimethylsilyl)phosphide could be a very efficient base to remove a proton from acetonitrile. (C) 2002 Wiley Periodicals, Inc.