Oxyphosphonium Enolate Equilibria in a (4+1)‐Cycloaddition Approach toward Quaternary C3‐Spirooxindole Assembly
作者:Eva M. Gulotty、Kevin X. Rodriguez、Erin E. Parker、Brandon L. Ashfeld
DOI:10.1002/chem.202100355
日期:2021.7.16
convergent (4+1)-cycloaddition strategy toward the construction of spirooxindole benzofurans that involves the intermediacy of an isatin-derived oxyphosphonium enolate is presented. Mechanistic investigations employing in situ NMR analysis of the reaction mixture revealed a correlation between phosphonium enolate structure and product distribution that was heavily influenced by the solvent and reaction temperature
Enantioselective [4 + 2] Cycloadditions of <i>o</i>-Quinone Methides: Total Synthesis of (+)-Mimosifoliol and Formal Synthesis of (+)-Tolterodine
作者:Carolyn Selenski、Thomas R. R. Pettus
DOI:10.1021/jo048703c
日期:2004.12.1
The first example of an enantioselectivecycloaddition of an o-quinone methide (o-QM) with a chiral enol ether is described along with the total synthesis of (+)-mimosifoliol and the formal synthesis of (+)-tolterodine. These syntheses exemplify a three-component, one-pot benzopyran approach for the construction of chiral benzylic junctions. Cycloadditions of various enol ethers and o-QMs are examined