Rainoldi G, Faltracco M, Lo Presti L, Silvani A, Lesma G
Dipartimento di Chimica, Università degli Studi di Milano, via Golgi 19, Milano, 20133, Italy.
Chem Commun (Camb). 2016 Oct 4;52(77):11575-8. doi: 10.1039/c6cc05838h. Epub 2016 Sep 7.
A diastereoselective, DABCO-catalyzed reaction of isatin-derived ketimines with allenoates is described. Exploiting the stereodirecting effect of the bulky tert-butanesulfinyl chiral auxiliary, the method provides an efficient access to single diastereoisomers of unprecedented spirocyclic oxindoles, bearing a 4-methyleneazetidine ring at the spiro junction. The versatility of the method is fully demonstrated by further transformations including the conversion to relevant spirocyclic oxindolo-β-lactams.
本文描述了一种非对映选择性的、由1,4-二氮杂双环[2.2.2]辛烷（DABCO）催化的异吲哚酮衍生的酮亚胺与丙二烯酸酯的反应。利用庞大的叔丁基亚磺酰基手性助剂的立体定向作用，该方法提供了一条有效途径，可获得前所未有的螺环氧化吲哚的单一非对映异构体，其在螺环连接处带有一个4-亚甲基氮杂环丁烷环。该方法的多功能性通过进一步的转化得以充分证明，包括转化为相关的螺环氧化吲哚-β-内酰胺。
