Dirhodium(II) tetrakis[N-tetrafluorophthaloyl-(S)-tert-leucinate], Rh2(S-TFPTTL)4, is an exceptionally efficient catalyst for enantioselective aminations of silyl enol ethers derived from acyclic ketones or alpha,beta-enones with [N-(2-nitrophenylsulfonyl)imino]phenyliodinane (NsN=IPh), providing N-(2-nitrophenylsulfonyl)-alpha-amino ketones in high yields and with enantioselectivities of up to 95% ee. The effectiveness of the present catalytic protocol has been demonstrated by an asymmetric formal synthesis of (-)-metazocine.

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Enantioselective syntheses Enantioselective syntheses O 0031 Dirhodium(II) Tetrakis[N-tetrachlorophthaloyl-(S)-tert-leucinate]: A New Chiral Rh(II) Catalyst for Enantioselective Amidation of C-H Bonds. -The amidation of benzylic C-H bonds with the phenyliodiane (II) is investigated in the presence of the title compound as catalyst. The observed enantioselectivities are the highest reported to date for Rh-catalyzed C-H amidation. -(YAMAWAKI, M.; TSUTSUI, H.; KITAGAKI, S.; ANADA, M.; HASHIMOTO*, S.; Tetrahedron Lett. 43 (2002) 52, 9561-9564; Grad. Sch. Pharm. Sci., Hokkaido Univ., Sapporo 060, Japan; Eng.) -Mais 12-035

-The enantioselective aziridination of alkenes with[N-(4-nitrophenylsulfonyl imino]phenyliodinane catalyzed by dirhodium (II) tetrakis[N-tetrachlorophthaloyl-(S)-tert-leucinate], Rh 2 (S-TCPTTL) 4 , is described.While such enantioselectivities are highly dependent on the properties of the alkenes, 2,2-dimethylchromene was found to be a particularly suitable substrate which can be efficiently transformed into the aziridine product in 98% yield with 94% ee.The enantioselective nitrene transfer reaction from [N-(arylsulfonyl)imino]phenyliodinanes to alkenes catalyzed by chiral transition metal complexes represents one of the most direct and powerful methods for the construction of optically active aziridines which are versatile building blocks for the synthesis of biologically important, nitrogen-containing molecules.11 Over the past fifteen years, substantial progress has been made in the development of enantioselective variants through catalysis by copper,

-The enantioselective aziridination of alkenes with[N-(4-nitrophenylsulfonyl imino]phenyliodinane catalyzed by dirhodium (II) tetrakis[N-tetrachlorophthaloyl-(S)-tert-leucinate], Rh 2 (S-TCPTTL) 4 , is described.While such enantioselectivities are highly dependent on the properties of the alkenes, 2,2-dimethylchromene was found to be a particularly suitable substrate which can be efficiently transformed into the aziridine product in 98% yield with 94% ee.The enantioselective nitrene transfer reaction from [N-(arylsulfonyl)imino]phenyliodinanes to alkenes catalyzed by chiral transition metal complexes represents one of the most direct and powerful methods for the construction of optically active aziridines which are versatile building blocks for the synthesis of biologically important, nitrogen-containing molecules.11 Over the past fifteen years, substantial progress has been made in the development of enantioselective variants through catalysis by copper,