Abstract
Asymmetric hetero Diels–Alder reaction of Danishefsky's dienes with glyoxylates is catalyzed in high enantioselectivity and cis ( endo)-diastereoselectivity by chiral (Phebox)RhCl 2(H 2O) complexes [Phebox=2,6-bis(oxazolinyl)phenyl], via the concerted [4+2] mechanism with perpendicular conformation of two carbonyl moieties of glyoxylates. Dibromide and difluoride complexes were newly synthesized and found to exhibit a slightly higher enantioselectivity of the hetero Diels–Alder products than the parent dichloride complex (Cl: 80% ee, Br: 82% ee, F: 84% ee).
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have