Catalytic process for the selective oxidation of organic tertiary polyphosphines to phosphine monooxides

A process for the selective oxidation of organic tertiary polyphosphines of the structure:

• R.sup.1 R.sup.2 P--Y--PR.sup.3 R.sup.4
• wherein
• each of R.sup.1, R.sup.2, R.sup.3, R.sup.4, are selected independently from the group consisting of alkyl containing up to about 8 carbon atoms, substituted alkyl containing up to about 8 carbon atoms, aryl, including phenyl, substituted aryl, aralkyl, ring-substituted aralkyl, heteroaryl, substituted heteroaryl, cycloalkyl, substituted cycloalkyl, or any 2 or more of R.sup.1 to R.sup.4 are joined together to form one or more ring(s) and or bicyclic rings;
• and
• Y is a bidentate radical selected from the group consisting of
• (CR.sup.5 R.sup.6).sub.n, where n is an integer from 1 to 4 and R.sup.5 and R.sup.6 are each selected from the group consisting of H, F, alkyl, containing up to about 8 carbon atoms, cycloalkyl, aryl, heteroaryl, aralkyl, vinyl and allyl or where R.sup.5 and R.sup.6 may be joined together to form a ring;
• (CR.sup.5 R.sup.6).sub.p X(CR.sup.5 R.sup.6).sub.q, where p and q are, independently, integers from 1 to 3 and X is selected from the group consisting of O, S, SO, SO.sub.2, NR.sup.5, N(O)R.sup.5, ›NR.sup.5 R.sup.6 !.sup.+, NR.sup.5 NR.sup.6, N.dbd.N, SiR.sup.5 R.sup.6, GeR.sup.5 R.sup.6, SnR.sup.5 R.sup.6, Hg, TlR.sup.5 ;
• cis-CR.sup.5 .dbd.CR.sup.6 ;
• cis-CR.sup.5 R.sup.6 CR.sup.5 .dbd.CR.sup.6 CR.sup.5 R.sup.6 ;
• CR.sup.5 R.sup.6 CR.sup.5 R.sup.6 CR.sup.5 .dbd.CR.sup.6 ;
• 1,2-phenylene;
• 1,2-naphthylene, 2,3-naphthylene and 1,8-naphthylene;
• 2,2'-biphenylene;
• 2,2'-(1,1'-binaphthylene);
• 2,2'-C.sub.6 H.sub.4 --X--C.sub.6 H.sub.4 ;
• cyclopropanediyl;
• 1,1'-ferrocenylene;
• 1,2-ferrocenylene;
• and
• 1,2-carboranediyl (C.sub.2 B.sub.10 H.sub.10);
• and
• wherein any of R.sup.1 to R.sup.6 and Y optionally contains additional remote, unreactive tertiary phosphine groups, to form the corresponding phosphine monooxide comprising the steps of:
• (a) contacting under oxidizing conditions said organic tertiary phosphine substrate with an oxidant selected from the group consisting of olefinic precursors vicinally disubstituted with good leaving groups selected from the group consisting of chloride, bromide, iodide, tosylate, mesylate, triflate and carboxylate, in the presence of a catalytically effective amount of a metal catalyst selected from the group consisting of, palladium, platinum, silver, gold, rhodium, ruthenium, osmium, nickel, cobalt and iron or alternate salt forms or complexes thereof optionally in the presence of a promoter comprising a source of iodide ion, and, optionally, recovering the corresponding monooxide product.