Silver(I)-Catalyzed Atroposelective Desymmetrization of <i>N</i>‑Arylmaleimide via 1,3-Dipolar Cycloaddition of Azomethine Ylides: Access to Octahydropyrrolo[3,4‑<i>c</i>]pyrrole Derivatives

A highly efficient Ag­(I)-catalyzed atroposelective desymmetrization of <i>N</i>-(2-<i>t</i>-butylphenyl)­maleimide via 1,3-dipolar cycloaddition of in situ generated azomethine ylides has been established successfully, affording a facile access to a series of biologically important and enantioenriched octahydropyrrolo­[3,4-<i>c</i>]­pyrrole derivatives in generally high yields (up to 99%) with excellent levels of diastereo-/enantioselectivities (up to 99% ee, >20:1 dr). Subsequent transformations led to fascinating 2<i>H</i>-pyrrole and polysubstituted pyrrole compounds without loss of stereoselectivity. The absolute configuration of the generated chiral axis has been unambiguously identified as (<i>M</i>) through single-crystal X-ray diffraction analysis. Furthermore, on the basis of the comprehensive experimental results and the absolute configuration of one of the cycloadducts, the origin of the stereoselectivity was proposed to be attributed to the steric congestion imposed by the bulky PPh₂ group of the chiral ligand and the <i>tert</i>-butyl group of <i>N</i>-(2-<i>t</i>-butylphenyl)­maleimide. The possible hydrogen bond interaction between the NH₂ group of the chiral ligand and one of the carbonyl groups of <i>N</i>-(2-<i>t</i>-butylphenyl)­maleimide is considered to facilitate stabilizing the transition state

Silver(I)-Catalyzed Enantioselective Desymmetrization of Cyclopentenediones: Access to Highly Functionalized Bicyclic Pyrrolidines

A highly enantioselective desymmetrization of prochiral cyclopentenediones via Ag­(I)-catalyzed asymmetric 1,3-dipolar cycloaddition of azomethine ylide has been developed successfully. The methodology performs well over a broad scope of substrates, which provides facile access to a series of highly functionalized bicyclic pyrrolidine/cyclopentane derivatives in good to high yields with excellent stereoselectivities

Ag(I)-Catalyzed Kinetic Resolution of Cyclopentene-1,3-diones

An efficient kinetic resolution of readily available racemic cyclopentene-1,3-diones has been developed via a Ag­(I)-catalyzed asymmetric 1,3-dipolar cycloaddition of azomethine ylides. This methodology shows good functional-group tolerance, delivering an array of synthetically valuable cyclopentene-1,3-diones with excellent stereoselectivity and generally high resolution efficiency (<i>s</i> = 48–226) accompanied by the biologically important fused pyrrolidine derivatives. Notably, this strategy allows facile access to the key intermediates for the synthesis of (+)-madindolines A and B

Ag(I)-Catalyzed Kinetic Resolution of Cyclopentene-1,3-diones

An efficient kinetic resolution of readily available racemic cyclopentene-1,3-diones has been developed via a Ag­(I)-catalyzed asymmetric 1,3-dipolar cycloaddition of azomethine ylides. This methodology shows good functional-group tolerance, delivering an array of synthetically valuable cyclopentene-1,3-diones with excellent stereoselectivity and generally high resolution efficiency (<i>s</i> = 48–226) accompanied by the biologically important fused pyrrolidine derivatives. Notably, this strategy allows facile access to the key intermediates for the synthesis of (+)-madindolines A and B