Asymmetric Cyclopropanation and Aziridination Reactions of Olefins Catalyzed by Cu(I)-Binaphthyldiimine Complexes

Abstract

The chiral Cu(I)-N,N′-bis(2,6-dichlorobenzylidene)-1,1′-binaphthyl-2,2′-diamine complex was found to be an efficient catalyst for asymmetric cyclopropanation and aziridination reactions of olefins with l-menthyl diazoacetate and [N-(p-tolylsulfonyl)imino]phenyliodinane, respectively. Among mono- and disubstituted olefins, 1,1-diarylethylenes showed extremely high enantioselectivities (up to 98% ee) in the cyclopropanation reactions in the presence of a chiral Cu(I)-catalyst (2 mol%). In the case of aziridination reactions catalyzed by the same Cu(I)-catalyst (10 mol%), the reaction of trans-substituted 3-aryl-2-propenoates and 1-substituted trans-3-aryl-2-propen-1-ones showed satisfactory results in term of the enantioselectivities (up to 98% ee).

New copper(I) and silver(I) triazolato-complexes: Synthesis, reactivity and catalytic activity in olefin cyclopropanation

“…On the contrary, the 13 C{ 1 H} NMR gave satisfactory information thanks to the occurrence of a broad signal at 169 ppm, attributable to the CHCOOEt group. It is worth mentioning that the resonance at 169 ppm in 13 C NMR could also derive from the insertion of the carbenic fragment into the O-H bond of the ligand [24].…”

“…A large variety of sp 2 -nitrogen based ligands, such as C 2 -symmetric semicorrins [8], bis(oxazolines) [9], optically active bipyridines [10] polypyrazolylborates [11] and diiminophosphoranes [12], have been used with the aim of enhancing the selectivity. Recently, high enantioselectivities were reached with binaphthyldiimines [13] and chiral bispidines [14].…”

Three‐Membered Heterocycles. Structure and Reactivity

“…Thus, trans-t-butyl cinnamate (44) was aziridinated stereospecifically and enantioselectively to provide the product in excellent yield [86]. A later report from another set of investigators using essentially identical conditions gave the same high enantioselectivity but significantly lower yield [87].…”

Alternative Coordination Modes in Palladium(II)‐Diimino‐Bispyridine Complexes with an Axially Chiral Biphenyl Backbone

“…[9] Palladium complexes with chiral bidentate bis-(oxazoline) ligands have been shown to be efficient in asymmetric allylic alkylation, [10] while biaryl Schiff base Cu complexes catalyze the aziridination of alkenes. [11] With a structurally rigid 6,6Ј-disubstituted biaryl ligand backbone, the configuration of the ligand is fixed and its axial chirality can efficiently be transmitted to the stereotopicity of the active site. [12] Biphenyl-bridged ligands form, in general, mononuclear complexes, [13] but binuclear complexes, e. g. with Cu II , have also been reported.…”