Chiral bispyridylamide metal complexes as catalysts for the enantioselective adddition of TMSCN to aldehydes
2004 (English)In: Journal of Organometallic Chemistry, ISSN 0022-328X, E-ISSN 1872-8561, Vol. 689, no 23, 3750-3755 p.Article in journal (Refereed) Published
The use of (1R,2R)-N,N'-bis(2-pyridinecarboxyamido)-1,2-diphenylethane metal complexes as catalysts for the enantioselective addition of trimethylsilyl cyanide to aldehydes is described. Enantioselectivities up to 70% ee were obtained with a Ti(IV) catalyst. Complexes with Zr(IV), Sc(III), Yb(III) and Cu(II) afforded less selective catalysts. For the Zr(IV) complex, a rate and selectivity enhancement was observed when adding 0.5 equiv. of water with respect to the catalyst. Studies of the metal complexes involved in the reaction were carried out by means of H-1 NMR spectroscopy. A Zr complex was shown by X-ray crystallography to exhibit distorted octahedral coordination, with the four nitrogen atoms of the doubly deprotonated ligand essentially in one plane.
Place, publisher, year, edition, pages
2004. Vol. 689, no 23, 3750-3755 p.
pyridylamide, asymmetric catalysis, cyanohydrins, Lewis acid, (salen)titanium complexes, trimethylsilyl cyanide, asymmetric addition
IdentifiersURN: urn:nbn:se:kth:diva-23902DOI: 10.1016/j.jorganchem.2004.06.014ISI: 000225312600010ScopusID: 2-s2.0-19344368243OAI: oai:DiVA.org:kth-23902DiVA: diva2:342601
QC 20100525 QC 201109162010-08-102010-08-102011-09-16Bibliographically approved