J. Bakos et al., Asymmetric hydroformylation of styrene catalyzed by platinum complexes of chiral diphosphites with atropisomeric terminal moieties, CAN J CHEM, 79(5), 2001, pp. 725-730
Citations number
39
Categorie Soggetti
Chemistry
Journal title
CANADIAN JOURNAL OF CHEMISTRY-REVUE CANADIENNE DE CHIMIE
To study the nature of steric and electronic effects of diphosphites, a nov
el diphosphite was synthesized and tested with regard of its catalytic perf
ormance in the hydroformylation of styrene catalyzed by platinum complexes.
The novel ligand 3 was prepared by the reaction of enantiomerically pure p
entane-2,4-diol with (S)-2-chloro-5,5',6,6',7,7',8,8'-octahydro-dinaphtho[2
,1-d:1',2'-f][1,3,2]dioxaphosphepine based on H-8-BINOL (H-8-BINOL = 5,5',6
,6',7,7',8,8'-octahydro-1,1'-bi-2-naphthol). For a comparative study, the B
INOL (1,1'-bi-2-naphthol) based analogue 4 of 3 has also been synthesized.
The highest chemoselectivity to aldehyde (71%) and regioselectivity to bran
ched aldehyde (85%) with an enantiomer excess (ee) of 86% was obtained with
the platinum(II)-SnCl2 catalytic system associated with (2S,4S)-bis(S)-3.