Catalytic Enantioselective Aziridination of Alkenes Using Chiral Dirhodium(II) Carboxylates

Abstract

-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,

Enantioselective Aziridination of Unactivated Terminal Alkenes Using a Planar Chiral Rh(III) Indenyl Catalyst

“…While catalytic methods have been developed using organocatalysts, transition metal-catalyzed methods have remained the predominant means of accessing chiral aziridines through this disconnection. Following the seminal work by Evans , and Jacobsen, the development of Cu­(II)-catalyzed methodologies using discreet or in situ-generated hypervalent imino-iodinane nitrene sources has received the most attention. − Since then, other methodologies have been developed using Ru­(II), − Co­(II), , Rh­(II), − Fe­(II), Mn­(III), and Ag­(I), along with a variety of unique ligand designs and nitrene sources, enabling both intra- and intermolecular stereoselective aziridinations. However, these methods have focused on the aziridination of activated alkenes such as styrenes and α,β-unsaturated systems (Scheme a, top).…”

Enantioselective Aziridination of Unactivated Terminal Alkenes Using a Planar Chiral Rh(III) Indenyl Catalyst

“…Following seminal work by Evans [11][12] and Jacobsen, 13 development of Cu(II) catalyzed methodologies have received the most attention using discreet or in situ generated hypervalent imino-iodinane nitrene sources. [14][15][16][17][18] Since then, other methodologies have been developed using Ru(II), [19][20][21] Co(II), [22][23] Rh(II), [24][25][26] Fe(II), 27 Mn(III), 28 and Ag(I), 29 along with a variety of unique ligand designs and nitrene sources, enabling both intra-and intermolecular stereoselective aziridinations. However, these methods have focused on the aziridination of activated alkenes such as styrenes and α,β-unsaturated systems (Scheme 1a, top).…”