Transferring Substituents from Alkynes to Furans and Pyrroles through Heteronorbornadienes as Intermediates: Synthesis of β-Substituted Pyrroles/Furans
作者:Javier García-Domínguez、Marina Carranza、Edijs Jansons、Ana T. Carmona、Inmaculada Robina、Antonio J. Moreno-Vargas
DOI:10.1021/acs.joc.3c01145
日期:2023.9.15
synthetic intermediates for the preparation of 3/4-substituted (β-substituted) furans/pyrroles is presented. The method lies in the inverse electron demand Diels–Alder (iEDDA) cycloaddition between a substituted heteronorbornadiene and an electron-poor tetrazine followed by spontaneous fragmentation of the resulting cycloadduct via two retro-Diels–Alder (rDA) reactions affording a β-substituted furan/pyrrole
3-F-alkyl-4-ethoxycarbonylfuranes have been prepared from 2-F-alkyl-3-ethoxycarbonyl-7-oxa-(2,2,1)-bicyclo hepta-2,5-dienes by retro Diels-Alder reactions with tetracyclone (2,3,4,5-tetraphenylcyclopentadienone).The products were characterised by elemental analysis, NMR H-1 and F-19, and Mass Spectrometry.