Tetraphosphorus ligands for catalytic hydroformylation and related reactions

A phosphorous ligand having the following formula:

• wherein i, j, k, l, m and n are, independently, H, R, Ar, substituted Ar, OR, OAr, COOEt, halide, SO2R, SO3H, SO2NHR, POR2, POAr2 or NR2, where R is an alkyl, substituted alkyl, aryl or substituted aryl and Ar is an aryl;
• X1-X4 are, independently, R, Ar, OR, OAr, pyrrole or substituted pyrrole, where R is an alkyl, substituted alkyl, aryl or substituted aryl and Ar is an aryl;
• and Y1, Y′1, Y2, Y′2, Y3, Y′3, Y4, Y′4, are, independently, R, Ar, OR, OAr, pyrrole or substituted pyrrole, where R is an alkyl, substituted alkyl, aryl or substituted aryl and Ar is an aryl, or where R, Ar, OR, OAr, pyrrole and substituted pyrrole are linked with a carbon to carbon bond, CH2, NH, NR or O.