Hydroformylation process using a symmetric bisphosphite ligand for improved control over product isomers

A hydroformylation process for producing two or more aldehydes comprising a normal aldehyde and one or more iso-aldehydes with a target N/I ratio, which N/I ratio is defined as a molar ratio of the normal aldehyde to the iso-aldehydes, the process comprising contacting under reaction conditions an α-olefin represented by formula (I):

• R—CH2—CH═CH2 (I)
• wherein R is selected from the group consisting of hydrogen, substituted and unsubstituted C1-9-alkyl moieties, with carbon monoxide and hydrogen in a reaction medium that is essentially free of an iso-olefin represented by formula (II):
• R—CH2—C(CH3)═CH2 (II)
• wherein R is as defined above, in the presence of a transition metal-ligand complex catalyst comprising a symmetric calixarene bisphosphite ligand represented by formula (III):
• wherein each R1 is the same and is selected from the group consisting of hydrogen and substituted or unsubstituted alkyl moieties;
• wherein each R2 is the same and is an amide moiety;
• and
• wherein each R3 is the same, each R4 is the same, and each R5 is the same, and wherein R3, R4, and R5 are independently selected from hydrogen, alkyl, alkaryl, alkoxy, aryloxy, keto, carbonyloxy, and alkoxycarbonyl moieties;
• which contacting occurs under a carbon monoxide partial pressure in a range from 6 psi (41 kPa) to 300 psi (2.1 mPa) to produce the two or more aldehydes with the target N/I ratio, which target N/I ratio is selectable over a range from 3 to 60 by controlling the carbon monoxide partial pressure.