In the presence of ZnCl₂, chiral protected amino-ketones and amino-aldehydes gave zinc enamino-complexes. Both enamine and iminium structures of these complexes were observed in ¹H and ¹³C NMR spectra depending on the solvent. Introduction of either an allyl or a hydrogen substituent was performed using allylmagnesium chloride or NaBH₄ in excess leading to various heterocycles. With the amino-ketones diastereoselectivity (de = 50) was observed respectively. Homoconiine and coniine precursors were prepared by this strategy.

中文翻译：

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杂环烯胺-锌配合物的合成作为氮α-位立体控制取代的前体

在存在ZnCl ₂的情况下，手性保护的氨基酮和氨基醛得到锌的氨基复合物。根据溶剂的不同，在¹ H和¹³ C NMR光谱中观察到了这些配合物的烯胺和亚胺鎓结构。使用过量的烯丙基氯化镁或NaBH ₄进行烯丙基或氢取代基的引入，从而导致各种杂环。用氨基酮 分别观察到非对映选择性（de＝ 50）。通过该策略制备高可可碱和甜氨酸前体。