ON THE STRUCTURE AND REACTIVITY OF LITHIUM DIISOPROPYLAMIDE (LDA) IN HYDROCARBON SOLUTIONS - FORMATION OF UNSOLVATED KETONE, ESTER, AND CARBOXAMIDE ENOLATES
ON THE STRUCTURE AND REACTIVITY OF LITHIUM DIISOPROPYLAMIDE (LDA) IN HYDROCARBON SOLUTIONS - FORMATION OF UNSOLVATED KETONE, ESTER, AND CARBOXAMIDE ENOLATES
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DOI：
10.1021/jo00014a019
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发表时间：
1991-07-05
影响因子：
3.6
通讯作者：
COLLUM, DB
中科院分区：
文献类型：
--
作者：
KIM, YJ;BERNSTEIN, MP;COLLUM, DB
描述了在己烷或甲苯中，通过无溶剂的二异丙基氨基锂（LDA）对酮、叔丁基酯和羧酰胺的烯醇化。 烯醇化物分离为光谱纯的白色（通常为结晶）固体。 烯醇化物在己烷中的溶解度范围从高度可溶到完全不溶。 醛、甲酯和丙酮的烯醇化提供复杂的混合物。 通过Li-6和N-15 NMR光谱法分析[Li-6]LDA和[Li-6，N-15]LDA在己烷中的情况显示出至少三种环状低聚物的平衡混合物的证据。
Enolization of ketones, tert-butyl esters, and carboxamides by solvent-free lithium diisopropylamide (LDA) in hexane or toluene are described. Enolates are isolated as spectroscopically pure, white (often crystalline) solids. Solubilities of the enolates in hexane range from highly soluble to completely insoluble. Enolizations of aldehydes, methyl esters, and acetone afford complex mixtures. Analysis of [Li-6]LDA and [Li-6, N-15]LDA in hexane by Li-6 and N-15 NMR spectroscopy show evidence of an equilibrium mixture of at least three cyclic oligomers.