BINOL-Based Ditopic Diphosphite Ligands - Synthesis, Evaluation and Regioselectivity Optimization of Catalytic Hydroformylation by 2(3) Factorial Design

• Type: Article in International Scientific Journal
• Date: 2014

Authors

Peixoto, AF (Author) FCUP; Abreu, AR (Author) Other; Almeida, AR (Author) Other; Neves, A (Author) Other; Abreu, PE (Author) Other; Moreno, MJSM (Author) Other; Bayon, JC (Author) Other; Pais, AACC (Author) Other; Pereira, MM (Author) Other

Journal

The Journal is awaiting validation by the Administrative Services.

Title: CURRENT ORGANIC SYNTHESIS

Vol. 11

Pages: 301-309

ISSN: 1570-1794

Indexing

ISI Web of Knowledge - 5 Citations

Scopus - 5 Citations

Other information

Authenticus ID: P-009-SEY

DOI: 10.2174/15701794113106660072

Abstract (EN): BINOL-based diphosphite ligands containing oxygen or nitrogen heteroatoms are currently a new class of promising ligands for homogeneous catalysis. Herein we present a useful strategy to synthesize ditopic (R)-BINOL-based diphosphites, containing pyridyl or propyl ether bridges between BINOL fragments in high isolated yields (50-92 %). Their rhodium complexes were evaluated in styrene hydroformylation, in which a moderate regioselectivity for the branched aldehyde was observed. The addition of a lithium salt led to a significant increase in the regioselectivity (25 %) for the branched aldehyde. This interesting observation has been rationalized based on a full two-level factorial design with 3 factors, including pressure, temperature and the Li/Rh ratio, using Rh/10 as model catalyst. The improvement of the regioselectivity in the presence of lithium salts has been interpreted through(31)PNMR spectroscopy and semi-empirical PM6 computational studies.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 9