NHC-Catalyzed Spiro Bis-Indane Formation via Domino Stetter−Aldol−Michael and Stetter−Aldol−Aldol Reactions
摘要:
Two novel domino NHC-catalyzed spirocyclizations are described herein, enabling the rapid construction of three new carbon-carbon bonds and a quaternary center with high diastereoselectivity. A variety of Spiro bis-indane structures are assembled in a single step from simple o-phthaldialdehyde derivatives.
The synthesis of spiro bis-indanes by means of N-heterocyclic carbene (NHC) catalysis is reported. The dimerization of various o-formylchalcone substrates or their combination with phthaldialdehyde derivatives under the catalysis of thiazolium-derived carbenes afforded Stetter-aldol-Michael products and Stetter-aldol-aldol products, respectively. The use of poor Michael acceptors in conjunction with