Gold-Catalyzed Oxa-Povarov Reactions for the Synthesis of Highly Substituted Dihydrobenzopyrans from Diaryloxymethylarenes and Olefins
作者:Vinayak Vishnu Pagar、Chang-Chin Tseng、Rai-Shung Liu
DOI:10.1002/chem.201403285
日期:2014.8.11
Oxa‐Povarov reactions involving readily available diaryloxymethylarenes and aryl‐substituted alkenes are reported. Their [4+2] cycloadditions were efficiently catalyzed by IPrAuSbF6 (IPr=1,3‐bis(diisopropylphenyl)imidazol‐2‐ylidene) with high diastereoselectivity. Product analysis revealed that the reactions likely proceed by a stepwise ionic mechanism, because both E‐ and Z‐configured β‐methylstyrene
据报道,Oxa-Povarov反应涉及容易获得的二芳氧基甲基芳烃和芳基取代的烯烃。IPrAuSbF 6(IPr = 1,3-双(二异丙基苯基)咪唑-2-亚烷基)具有高的非对映选择性,可有效催化它们的[4 + 2]环加成反应。产物分析表明,反应可能是通过逐步的离子机理进行的,因为E和Z构型的β-甲基苯乙烯均以相同的比例产生相同的环加合物。