Accessing Skeletal Diversity under Iron Catalysis using Substrate Control: Formation of Pyrroles versus Lactones
作者:Benito Alcaide、Pedro Almendros、M. Teresa Quirós
DOI:10.1002/adsc.201100049
日期:2011.3.7
Worthy of note, in contrast to the iron‐catalyzed reactions of β‐lactam allenols which lead to γ‐lactones, the reaction of β‐lactam alkynols under identical conditions gives pyrroles. The gold‐catalyzed 6‐endo aminocyclization of these allenic γ‐lactones formed fused dihydropyridines. The iron‐catalyzed formation of pyrroles may proceed through a Meyer–Schuster rearrangement followed by β‐lactam ring opening
由丙烯腈β-内酰胺醛制备的2-氮杂环丁酮系链的炔醇和烯丙醇用作氯化铁(III)催化发散扩环反应的起始原料。值得注意的是,与β-内酰胺烯醇的铁催化反应会生成γ-内酯相反,β-内酰胺醇在相同条件下的反应会生成吡咯。这些烯丙基γ-内酯的金催化6-内氨基氨基环化形成了稠合的二氢吡啶。吡咯的铁催化形成可通过迈耶-舒斯特重排进行,然后通过氨基攻击酮使β-内酰胺开环和环化。