Gold-Catalysed Synthesis of Exocyclic Vinylogous Amides and β-Amino Ketones: A Detailed Study on the 5-<i>exo</i>/6-<i>endo</i>-<i>dig</i>Selectivity, Methodology and Scope
作者:Dina Scarpi、Stefano Begliomini、Cristina Prandi、Alberto Oppedisano、Annamaria Deagostino、Enrique Gómez-Bengoa、Béla Fiser、Ernesto G. Occhiato
DOI:10.1002/ejoc.201500205
日期:2015.5
6-alkynyl-3,4-dihydro-2H-pyridines, which gives synthetically useful vinylogous amides (β-enaminones), has been studied in detail, in order to optimize the reaction conditions, enlarge the scope and gain insight into the mechanism and the structural features that selectively favour the 6-endo-dig oxyauration of the triple bond. Experimental studies and DFT calculations demonstrate that the 6-endo-dig approach
已详细研究了 N-Boc 保护的 6-炔基-3,4-二氢-2H-吡啶的金(I)催化反应,该反应产生了合成有用的乙烯基酰胺(β-烯胺酮),以优化反应条件,扩大范围并深入了解选择性地有利于三键 6-endo-dig 氧化的机制和结构特征。实验研究和 DFT 计算表明,6-endo-dig 方法不适用于取代炔烃,而对于末端炔烃,5-exo-dig 环化占优势,尽管 C-6 处的角度大(120°)。用 N-Cbz 保护的 2-炔基哌啶观察到相同的选择性。使用这些化合物,由于 6-endo-dig 攻击取代的三键,获得了 β-氨基酮。