Reaction of compounds with a H-P bond with Schiff-bases

Addition of compounds with a P-H bond to Schiff bases of both simple and ma crocyclic compounds proceeds smoothly as a non catalysed thermally initiali sed reaction in an inert solvent. For macrocyclic systems and bulky phospho rus substituents a stereoselective formation of the trans isomer was confir med by X ray analysis. The addition is reversible, and the reverse reaction is catalysed by Lewis acids, The trans orientation of phosphorus substitue nts on the macrocycle ring, the stereochemical rigidity of molecules and re versibility of the addition limit the use of the compounds formed in such m anner as ligands.