Recent progress in a chiral multinucleating system utilizing tartaric acid esters.
In order to develop a practical method for the construction of chiral molecules, we have designed a novel chiral reaction system possessing multi-metal centers utilizing tartaric acid ester as a chiral auxiliary. Based on this concept, we have developed an asymmetric 1,3-dipolar cycloaddition reaction of azomethine imines, an asymmetric hetero Diels-Alder reaction of nitroso compounds, an asymmetric Diels-Alder reaction of o-quinodimethanes. Furthermore, an asymmetric nucleophilic addition of alkynylzinc reagents, prepared in situ from dialkylzinc and 1-alkynes, to nitrones was achieved with high level of stereocontrol. In the last case, the addition of methylzinc salt of a product-like racemic hydroxylamine was found to be effective for unprecedented enhancement of enantioselectivity.
Ukaji
Yutaka
Y
Division of Material Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma, Kanazawa, Ishikawa 920-1192, Japan. ukaji@kenroku.kanazawa-u.ac.jp
Inomata
Katsuhiko
K