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3001984 
Journal Article 
Synthesis of quinazolinone-based aziridine diols as chiral ligands: dual stereoselectivity in the asymmetric ethylation of aryl aldehydes 
Celik, S; Cakici, M; Kilic, H; Sahin, E 
2015 
1 
Tetrahedron: Asymmetry
ISSN: 0957-4166 
26 
2-3 
152-157 
WOS:000349500400011 
A new class of quinazoline-based enantiomerically pure aziridine diols 4a-d were prepared from the aziridination of mesityl oxide 3 with in situ generated 3-acetoxyaminoquinazolinone (S)-2b followed by NaBH4 reduction. Aziridine diols 4a-d were purified by means of column chromatography on silica gel and their stereochemistries were assigned by X-ray crystallography and NMR analysis. These aziridine diols 4 were evaluated as chiral ligands in the asymmetric addition of diethylzinc to aryl aldehydes, and ligand (S,R,R)-4a yielded (R)-1-phenylpropanol derivatives with up to 92% ee, while the diastereomer (S,S,R)-4c gave the opposite enantiomers (S)-1-phenylpropanol derivatives with up to 86% ee. The results demonstrate that switching the configuration of the aziridine alcohol moiety in ligand gives a remarkable reversal of enantioselectivity in the asymmetric addition of diethylzinc to aryl aldehydes. (C) 2015 Elsevier Ltd. All rights reserved.