Synthesis, Reactions, and Molecular Structures of Ethylzinc Enolates of Chiral N‐Substituted β‐Carbonyl Sulfoximines

The preparation, structural characterization, and reactivity of ethylzinc‐containing enolates and organometallics derived from β‐carbonyl sulfoximines are reported. X‐ray crystal structures show significant differences between aggregated species obtained from β‐keto and β‐amido sulfoximines. Whereas the former gives an O ‐metalated ethylzinc enolate, the latter crystallizes as C ‐metalated carbonyl species. NMR investigations reveal the presence of chelated zinc enolates in solution. The relationship between structure and reactivity is demonstrated by the reaction profiles of the ethylzinc‐containing compounds. A high diastereoselectivity (> 90% de ) was observed in the aldol reaction between the metalated β‐amido sulfoximine and benzaldehyde in the presence of trimethylsilyl chloride.