Organic Superbases in Annulation with Propargylic Alcohols: Straightforward Synthesis of the Functionalized Oxazolopyrrolohexahydropyrimidine and Oxazolohexahydropyrimidoazepine Scaffolds
作者:Boris A. Trofimov、Olesya A. Shemyakina、Anastasiya G. Mal'kina、Anton V. Stepanov、Ol'ga G. Volostnykh、Igor' A. Ushakov、Alexander V. Vashchenko
DOI:10.1002/ejoc.201600977
日期:2016.11
alcohols [EWG = CN, C(O)Ph, CO2Me] to afford functionalized condensed hexahydropyrimidine systems, [1,3]oxazolo[3,2-a]pyrrolo[2,1-b]hexahydropyrimidines and [1,3]oxazolo[3′,2′:3,4] hexahydropyrimido[1,2-a]azepines, in good to high yields. The reactions proceeded regioselectively and, in most cases, stereoselectively under mild conditions (without catalyst, 20–25 °C). The synthesized compounds, owing to their
流行的有机超强碱 1,5-二氮杂双环 [4.3.0]non-5-ene (DBN) 和 1,8-二氮杂双环 [5.4.0]undec-7-ene (DBU) 与缺电子的炔丙醇进行了环化。 EWG = CN, C(O)Ph, CO2Me] 提供功能化的缩合六氢嘧啶系统、[1,3] 恶唑并[3,2-a] 吡咯并[2,1-b] 六氢嘧啶和 [1,3] 恶唑并[3] ',2':3,4] 六氢嘧啶并[1,2-a]氮杂,收率高。反应以区域选择性进行,在大多数情况下,在温和条件下(无催化剂,20-25°C)立体选择性地进行。由于其潜在的丰富化学性质,合成的化合物是基于嘧啶的药物的新型有前途的前体。