Abstract
Three main mechanistic pathways are now evident when Grignard, organolithium, organocopper, or transition metal anions are used as reagents for reactions with halogeno-phosphazenes-substitution, metal-halogen exchange, and skeletal cleavage. Use of these reaction pathways allows the synthesis of species such as I-X. A general mechanistic theory of these reactions is presented, together with an application of these mechanisms to macromolecular synthesis.