Dirhodium Tetracarboxylates Derived from Adamantylglycine as Chiral Catalysts for Enantioselective C−H Aminations
摘要:
The dirhodium tetracarboxylate, Rh-2(S-TCPTAD)(4), derived from adamantylglycine, is an effective chiral catalyst for both inter- and intramolecular C-H aminations.
Dirhodium(II) tetrakis[N-tetrachlorophthaloyl-(S)-tert-leucinate], characterized by substitution of chlorine atoms for four hydrogen atoms on the phthalimido group in the parent dirhodium(II) complex has been found to be well suited for enantioselective amidation of benzylic C-H bonds with [(4-nitrophenyl)sulfonylimino]phenyliodinane. The observed enantioselectivity of up to 84% ee is the highest reported to date for dirhodium(II) complex-catalyzed C-H amidations. (C) 2002 Elsevier Science Ltd. All rights reserved.