The Condensation of Ylidyl Chlorophosphines with Phosphines and Bis(diphenylphosphino)methane and -amine.-Reaction of ylidyl chlorophosphanes, e.g. (I), with trimethylsilyl phosphanes (II), methanide (V), and amide (VIII) results in the formation of ylidyl diphosphanes, e.g. (III), triphosphanes, e.g. (IV), ylidyl diphosphonium ylides, e.g. (VI), which rearranges within one day into isomeric ylidyl triphosphanyl methane (VII), amino analogues, e.g. (IX), which cyclizes in solution at room temperature within two days by intramolecular alkylation to give the azatriphosphole derivative (X), and cyclic products (XI) and (XII) on a direct way. The structures of all reaction products are determined by 31 P NMR spectroscopic analyses and, in case of (X), by X-ray analysis. -(