Abstract: A hydroformylation process for preparating a terminal aldehyde involves reacting an ethylenically unsaturated organic compound with carbon monoxide and hydrogen in the presence of a catalyst system iridium or rhodium and a bidentate organic phosphite ligand wherein the two phosphorus atoms of the phopshite ligand are linked with a 2,2'-dihydroxyl-1,1'-binapthalene bridging group having the following structure (Q): ##STR1## in which R.sup.1 and R.sup.2 are substituents other than hydrogen and in which R.sup.3 and R.sup.4 are the same or different substituted monovalent aryl groups and/or any one of OR.sup.3 and OR.sup.4 connected to one phosphorus atom forms an --O--R.sup.5 --O-group, where R.sup.5 is a divalent organic group containing one or two aryl groups.

Abstract: A hydroformylation catalyst composition comprising iridium or rhodium and a bidentate organic phosphite ligand wherein the two phosphorus atoms of the phopshite ligand are linked with a 2,2'-dihydroxyl-1,1'-binapthalene bridging group having the following structure (Q): ##STR1## in which R.sup.1 and R.sup.2 are substituents other than hydrogen.

Abstract: The invention relates to a process for the preparation of 5-formylvaleric acid or the corresponding 5-formylvalerate by hydroformylation of 3-pentenoic acid or 3-pentenoate ester with carbon monoxide and hydrogen in the presence of a catalyst comprising of rhodium and a phosphite ligand, wherein the phosphite ligand is represented by the following general formula ##STR1## where R.sup.1 and R.sup.2 are the same or different aromatic organic groups and where A is an n-valent group or atom and where n is an integer chosen upwards of 2 and where the respective ?--O--P(OR.sup.1)(OR.sup.2)! group may be the same group or different groups and where the phosphite forms a chelate-type complex with rhodium.

Abstract: A process to prepare a multidentate phosphite compound according to the general formula (1) ##STR1## in which n is 2-6, R is an n-valent organic group and R.sup.1 and R.sup.2 are fused aromatic ring systems with 2 or more rings, which rings are substituted on the ortho position relative to the oxygen atom only with hydrogen, by first preparing a phosphorochloridite compound from a R.sup.1 --OH and R.sup.2 --OH alcohol compound and a phosphorus chloride compound and subsequently contacting the phosphorochloridite compound with an alcoholic compound according to R--(OH).sub.n, wherein the phosphorochloridite is prepared by performing the two steps in a solvent:a) contacting a compound with the general formula: ##STR2## in which R.sup.3 and R.sup.4 are C.sub.1 -C.sub.4 alkyl groups, with the R.sup.1 OH and R.sup.2 OH compounds, andb) contacting the resulting compound of step (a) which has the formula (3): ##STR3## with HY, wherein Y is a halogen.

Abstract: The invention relates to a process for preparing an aldehyde compound by hydroformylation of an ethylenically unsaturated organic compound, using a catalyst system which includes a Group VIII metal and a novel bidentate phosphite ligand. The bidentate phosphite ligand has a chemical structure according to formula (1), ##STR1## wherein R.sup.1 and R.sup.3 are respectively substituted or unsubstituted organic groups which may be the same or different, and wherein R.sup.2 is a substituted or unsubstituted tetravalent organic group.

Abstract: The invention relates to a process for the preparation of a 5-formylvalerate ester by hydroformylating a mixture of pentenoate esters in the presence of a catalyst system which catalyst system comprises a metal from group 8-10 of the Periodic Table of Elements and a mono- or multidentate organic phosphorous ligand, wherein the mixture of pentenoate esters contains less than 500 ppm hydroperoxide compounds.