Publication

Catalytic Kinetic Resolution by Enantioselective Aromatization: Conversion of Racemic Intermediates of the Barton-Zard Reaction into Enantioenriched 3-Arylpyrroles

Qian Wang, Jieping Zhu, Sheng-Cai Zheng
2019
Journal Articles

Abstract

Racemic 3,4-dihydro-2H-pyrroles, hypothetical intermediates of the Barton–Zard reaction, were synthesized in a highly diastereoselective manner and fully characterized for the first time. Kinetic resolution of the dihydropyrroles with a quinine-derived thiourea afforded the (+)-3-arylpyrrole products and recovered (+)-3,4-dihydro-2H-pyrroles with high efficiency (s-factor up to 153). The resolved (+)-3,4-dihydro-2H-pyrroles underwent subsequent aromatization with a quinidine-derived thiourea catalyst to afford (@)-3-arylpyrroles with excellent central-to-axial chirality transfer. In contrast to the well-accepted Barton–Zard mechanism, the aromatization of the 3,4-dihydro-2H-pyrroles in the presence of a bifunctional catalyst is believed to proceed by an unprecedented sequence involving syn elimination of HNO2 and aromatization.

Official source

https://infoscience.epfl.ch/entities/publication/dab065b0-4b50-4add-b244-1ecc04214fa2

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Qian Wang, Jieping Zhu, Sheng-Cai Zheng
2019
Journal Articles

Abstract

Official source

https://infoscience.epfl.ch/entities/publication/dab065b0-4b50-4add-b244-1ecc04214fa2

About this result

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