Cationic Gold- and Silver-Catalyzed Cycloisomerizations of Propargylic Ureas: A Selective Entry to Oxazolidin-2-imines and Imidazolidin-2-ones
作者:Olga P. Pereshivko、Vsevolod A. Peshkov、Jeroen Jacobs、Luc Van Meervelt、Erik V. Van der Eycken
DOI:10.1002/adsc.201200905
日期:2013.3.11
gold(I) catalysis generally resulted in a formation of oxazolidin‐2‐imines as major products while the application of silver(I) triflate selectively provided the corresponding imidazolidin‐2‐ones. An attempt to rationalize the observed chemoselectivity is described. The scope of both processes was demonstrated through the use of variously substituted secondary propargylic amines.
进行了过渡金属催化的仲炔丙基胺和异氰酸甲苯酯原位衍生的炔丙基脲的环异构化反应的研究。在两个模型实例上彻底研究了催化体系对反应结果的影响,从而建立了针对O-和N的两个选择性方案环化。阳离子金(I)催化的应用一般会导致恶唑烷-2-亚胺的形成,而主要产物是三氟甲磺酸银(I)选择性地提供了相应的咪唑烷-2-亚胺。描述了合理化观察到的化学选择性的尝试。通过使用各种取代的仲炔丙基胺证明了这两种方法的范围。