Accessing Skeletal Diversity under Iron Catalysis using Substrate Control: Formation of Pyrroles versus Lactones
Accessing Skeletal Diversity under Iron Catalysis using Substrate Control: Formation of Pyrroles versus Lactones
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DOI：
10.1002/adsc.201100049
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发表时间：
2011-03-07
影响因子：
5.4
通讯作者：
Teresa Quiros, M.
中科院分区：
文献类型：
--
作者：
Alcaide, Benito;Almendros, Pedro;Teresa Quiros, M.
2-氮杂环丁酮连接的炔醇和联烯醇，容易地从丙叉β-内酰胺醛制备，用作起始材料的发散扩环反应由氯化铁（III）催化。值得注意的是，与β-内酰胺联烯醇的铁催化反应生成γ-内酯相反，β-内酰胺炔醇在相同条件下的反应生成吡咯。这些丙二烯γ-内酯的金催化6-内氨基环化形成稠合的二氢吡啶。铁催化的吡咯的形成可以通过Meyer-Schuster重排进行，然后通过氨基攻击酮进行β-内酰胺开环和环化。
2-Azetidinone-tethered alkynols and allenols, readily prepared from a propanylidene beta-lactam aldehyde, were used as starting materials for divergent ring expansion reactions catalyzed by iron(III) chloride. Worthy of note, in contrast to the iron-catalyzed reactions of beta-lactam allenols which lead to gamma-lactones, the reaction of beta-lactam alkynols under identical conditions gives pyrroles. The gold-catalyzed 6-endo aminocyclization of these allenic gamma-lactones formed fused dihydropyridines. The iron-catalyzed formation of pyrroles may proceed through a Meyer-Schuster rearrangement followed by beta-lactam ring opening and cyclization by attack of the amino group to the ketone.