Efficient Asymmetric Simmons-Smith Cyclopropanation and Diethylzinc Addition to Aldehydes Promoted by Enantiomeric Aziridine-Phosphines

Aleksandra Buchcic-Szychowska,Anna Zawisza,Justyna Adamczyk,Lena Marciniak,Stanisław Leśniak,Adam Marek Pieczonka,Michał Rachwalski

doi:10.3390/catal11080968

Aleksandra Buchcic-Szychowska, Anna Zawisza + Show 5 more

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https://doi.org/10.3390/catal11080968

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Abstract

During an implementation of current research, a set of optically pure chiral aziridines and aziridine imines bearing a phosphine moiety was prepared with high values of chemical yield. The above chiral heteroorganic derivatives were tested for catalytic utility as chiral ligands in asymmetric Simmons-Smith cyclopropanation and asymmetric diethylzinc addition to various aldehydes. Most of the desired products were formed in high chemical yields, with satisfactory values of enantiomeric excess (sometimes more than 90%) and diastereomeric ratios (in case of cyclopropanation reaction).

Highlights

The asymmetric construction of chiral non-racemic organic compounds is still an extremely important issue for many research teams around the world
The use of n-butyraldehyde (Table 4, entry 1), 2- and 4-methyl, methoxy, bromo- and 4-trifluoromethylbenzaldehydes (Table 4, entries 2–8) led to the corresponding chiral alcohols in chemical yields with enantioselectivities up to 90%
The corresponding cyclopropanation and addition products were achieved in satisfactory chemical yields and with a high level of enantioselectivity and diastereoselectivity

Summary

Introduction

The asymmetric construction of chiral non-racemic organic compounds is still an extremely important issue for many research teams around the world Both the chemical yield and optical purity of the desired products of stereocontrolled synthesis depend on the selection of an appropriate promoter for such a reaction. A cyclopropane ring with unusual electronic and steric properties is present in many natural products [10] and drugs [11,12,13,14,15] Molecules containing this three-membered motif can be constructed in transformations with or without transition metals [16] in the presence of, e.g., complexes of porphyrin [17], proline derivatives [18,19], chiral phase-transfer catalysts [20] or as demonstrated in our laboratory, using chiral aziridinyl ligands containing sulfinyl moiety [21]

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