High performance phosphite ligands containing various numbers of | 19857
Journal of Chemical Engineering & Process Technology

Journal of Chemical Engineering & Process Technology
Open Access

ISSN: 2157-7048


High performance phosphite ligands containing various numbers of structural units for n-regioselective hydroformylation of olefins

5th World Congress on Catalysis and Chemical Engineering

September 05-06, 2018 Tokyo, Japan

Baoxin Zhang, Detlef Selent and Armin Borner

Leibniz Institute for Catalysis, Germany

Posters & Accepted Abstracts: J Chem Eng Process Technol

Abstract :

In comparison to phosphines, phosphite is stubborner ligands towards oxidation and therefore finds numerous catalytic applications at each scale. Especially in Rh-catalyzed regioselective hydroformylation of internal olefins, they are indispensable in the isomerization in favor of linear products. Starting from a prototype of all monophosphites tris(2,4-ditert- butylphenyl) phosphite, which has already been applied in an industrial scale, a new type of polyphosphites containing two and four the similar structural units were prepared. Their catalytic performances as well as hydrolytic stabilities were compared. In Rh-catalyzed hydroformylation of n-octenes, when the phosphite unit of the ligands was increased, the best yield was obtained from the reaction with the biphosphite. The n-selectivity is improved with the increased phosphite moiety, whilst the activity decreases. The regioselectivity is kinetically controlled. Lowering syngas pressure benefits the n-selectivity but decreases the catalyst activity. Besides, the hydrolysis pathway of one of the prepared biphosphites was clarified with in situ NMR spectroscopy. Surprisingly, its first step degradation was conducted simultaneously through three routes. The biphosphite cannot build a metal complex in a chelating manner. Instead, a binuclear Rh-complex was formed, which can further stabilize the ligand towards hydrolysis.

Biography :

Baoxin Zhang has completed his PhD majoring Organometallic Chemistry from Technical University of Darmstadt in Germany. He is currently a Research Fellow at Leibniz Institute for Catalysis (LIKAT) in Rostock. In the laboratory of Evonik Advanced Catalysis, he is doing research in homogeneous catalysis for hydroformylation and development of phosphorus ligands.