Transition metal-catalyzed intramolecular [4 + 2] cycloadditions: Mechanistic and synthetic investigations
作者:Paul A. Wender、Thomas E. Smith
DOI:10.1016/s0040-4020(97)10223-x
日期:1998.2
The nickel-catalyzed intramolecular cycloaddition of dienes with unactivatable alkynes is found to proceed under mild conditions while the corresponding Diels-Alder cycloaddition of the same substrates either fails or occurs only under forcing conditions. The nickel-catalyzed cycloaddition is also shown to occur with retention of stereochemistry and is not significantly influenced by electronic effects
发现二烯与不可活化的炔烃的镍催化的分子内环加成反应在温和条件下进行,而相同底物的相应Diels-Alder环加成反应要么失败,要么仅在强迫条件下发生。还显示了镍催化的环加成反应,其保留了立体化学,并且不受电子效应的显着影响。最后,该催化过程显示适用于有角度取代的自行车的合成,包括类固醇和维生素D的CD环系统。