Lithium phosphoramides are fairly unreactive with respect to alkylating agents. Their action is shown by the formation of a β-lithium amide. This bimetallic structure undergoes either bisalkylation or cyclisation according to experimental conditions; a cyclic intermediate is postulated to account for these observations.
preparation and reactivity of lithium or sodium phosphoramidates bearing an oxo- or nitro-υ-haloalkyl group is reported. These reagents by intramolecular cyclization lead with good yields to diazaphospholanes and oxazaphospholanes or phosphorinanes.