Ni Chunjie, Yuan Yuejie, Zhang Yuwen, Chen Jiangfei, Wang Dong, Tong Xiaofeng
College of Chemistry and Molecular Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China.
Org Biomol Chem. 2017 Jun 7;15(22):4807-4810. doi: 10.1039/c7ob00688h.
Here is reported the DMAP-catalyzed addition/(4 + 2) annulation domino reaction of δ-acetoxy allenoate with either salicylaldehyde-derived oxadiene or pyrrolealdehyde-derived oxadiene, which provides a facile method toward polycyclic frameworks. A cationic intermediate, 3-ammonium-2,4-dienoate, is proposed to be involved via an addition-elimination process between an allenoate and a catalyst, which is capable of undergoing addition with either O- or N-nucleophile and subsequent (4 + 2) annulation with oxadiene.
本文报道了在4-(N,N-二甲基氨基)吡啶(DMAP)催化下，δ-乙酰氧基丙烯酸酯与水杨醛衍生的二烯醚或吡咯醛衍生的二烯醚发生加成/(4 + 2)环化串联反应，该反应为构建多环骨架提供了一种简便方法。有人提出，一个阳离子中间体，即3-铵基-2,4-二烯酸酯，是通过丙烯酸酯与催化剂之间的加成-消除过程产生的，它能够与O-或N-亲核试剂发生加成反应，随后与二烯醚进行(4 + 2)环化反应。
