Facile Access to Functionalized Spiro[indoline-3,2鈥?pyrrole]-2,5鈥?diones via Post-Ugi Domino Buchwald鈥揌artwig/Michael Reaction
文摘
A novel access to spiro[indoline-3,2鈥?pyrrole]-2,5鈥?diones is presented via a palladium-catalyzed post-Ugi cascade cyclization approach involving a Buchwald鈥揌artwig/Michael reaction sequence. The method allows the easy construction of a library of spirooxindoles in moderate to good yields starting from readily available precursors. In addition, alkynoic acids are replaced with 伪,尾-unsaturated acids leading to variably substituted spirooxindoles.