Transition metal complex catalyzed reactions

A hydroformylation process for producing aldehydes which comprises reacting an olefinically unsaturated organic compound with carbon monoxide and hydrogen in the presence of a rhodium complex catalyst consisting essentially of rhodium complexed with carbon monoxide and a diorganophosphite ligand, and in the added presence of a free diorganophosphite ligand, wherein the diorganophosphite ligand complexed with the rhodium and the free diorganophosphite ligand are each individually ligands having the formula ##STR81## wherein W represents an unsubstituted or substituted monovalent hydrocarbon radical;

• wherein each Ar group represents an identical or different substituted or unsubstituted aryl radial, wherein each y individually has a value of 0 to 1, wherein Q is a divalent bridging group selected from the class consisting of --CR.sup.1 R.sup.2 --, --O--, --S--, --NR.sup.3 --, --SiR.sup.4 R.sup.5 -- and --CO--, wherein each R.sup.1 and R.sup.2 radical individually represents a radical selected from the group consisting of hydrogen, alkyl of 1 to 12 carbon atoms, phenyl, tolyl and anisyl, wherein each R.sup.3, R.sup.4, and R.sup.5 radical individually represents --H or --CH.sub.3, and wherein n has a value of 0 to 1, and wherein the hydroformylation reaction conditions comprise a reaction temperature in the range of from about 45.degree. C. to about 200.degree. C., to a total gas pressure of hydrogen, carbon monoxide and olefinically unsaturated organic compound of from about 1 to about 10,000 psia, a H.sub.2 :CO molar ratio of gaseous hydrogen to carbon monoxide in the range of from about 1:10 to 100:1, and wherein the reaction medium contains at least one mole of free diorganophosphite ligand per mole of rhodium present in the reaction medium.