South African Journal of Chemistry
versão On-line ISSN 1996-840X
versão impressa ISSN 0379-4350
PAWAR, Sunayna S. et al. Comparison of tetrahydroisoquinoline (TIQ) thiazole and oxazoline ligands for asymmetric Henry reactions. S.Afr.j.chem. (Online) [online]. 2012, vol.65, pp.23-29. ISSN 1996-840X.
A series of novel C1 symmetric thiazole ligands with a tetrahydroisoquinoline (TIQ) backbone were synthesized. Their application in the catalytic asymmetric Henry reaction was investigated with comparison to a corresponding TIQ oxazoline ligand. The Cu(II)-oxazoline complex was more reactive and furnished moderate enantioselectivities up to 61:36 (syn:anti) with 75:25 diastereomeric excess, while the Cu(II)-thiazole complexes had lower selectivity. This is the first example where a direct comparison between an N, N-type thiazole and oxazoline ligands has been studied.
Palavras-chave : Tetrahydroisoquinoline; thiazole; oxazoline; Henry reaction; enantioselectivity.