Base-Mediated Selective Synthesis of Diversely Substituted <i>N</i>-Heterocyclic Enamines and Enaminones by the Hydroamination of Alkynes
作者:Megha Joshi、Monika Patel、Rakesh Tiwari、Akhilesh K. Verma
DOI:10.1021/jo300782n
日期:2012.7.6
Regio- and stereoselective alkynylation of various N-heterocycles 1a–l usingpotassium and cesium salts in DMSO is described. Terminal alkynes 2a–k and internal alkynes 4a–f provided the kinetically stable Z-enamines 3a–l and 5a–i in good to excellent yields using KOH at 120 °C. Addition of heterocyclic amines to 1,3- and 1,4-diethynylbenzene 6a–b provided the mixture of E/Z isomers with KOH; however