Divergent Synthesis of Oxa‐Cyclic Nitrones through Gold(I)‐Catalyzed 1,3‐Azaprotio Transfer of Propargylic α‐Ketocarboxylate Oximes: Experimental and DFT Studies
作者:Chunhong Wang、Qi Cui、Zhixin Zhang、Zhu‐Jun Yao、Shaozhong Wang、Zhi‐Xiang Yu
DOI:10.1002/chem.201901522
日期:2019.7.25
α‐ketocarboxylate oximes, a new type of alkynyl oximes featuring an ester tether, has been explored by taking advantage of gold catalysis. The incorporation of an oxygen atom to the chain of alkynyl oximes led to the formation of two different oxa‐cyclic nitrones. It was found that internal alkynyl oximes with an E‐configuration deliver five‐membered nitrones, whereas terminal alkynyl oximes with an E‐configuration
通过金催化研究了炔丙基α-酮羧酸酯肟的一种新型的炔丙基肟的1,3-氮杂酚的转移。氧原子与炔肟肟链的结合导致形成两种不同的氧杂环硝酮。结果发现,与内部炔肟Ë构型提供五元硝酮,而终端炔肟与Ë配置提供六元硝酮。DFT对四种可能途径的计算支持了C-N和C-H键的逐步形成,其中1,3-酰氧基迁移与1,3-氮杂旋转转移竞争,特别是在内部炔基肟的情况下。通过计算研究了羰基中氧和肟中氮的相对亲核性质,炔烃的电子效应以及环系统的影响。