Asymmetric Synthesis of Spirooxindoles via Nucleophilic Epoxidation Promoted by Bifunctional Organocatalysts

Molecules : a Journal of Synthetic Chemistry and Natural Product Chemistry
Martina MiceliTecla Gasperi

Abstract

Taking into account the postulated reaction mechanism for the organocatalytic epoxidation of electron-poor olefins developed by our laboratory, we have investigated the key factors able to positively influence the H-bond network installed inside the substrate/catalyst/oxidizing agent. With this aim, we have: (i) tested a few catalysts displaying various effects that noticeably differ in terms of steric hindrance and electron demand; (ii) employed α-alkylidene oxindoles decorated with different substituents on the aromatic ring (11a-g), the exocylic double bond (11h-l), and the amide moiety (11m-v). The observed results suggest that the modification of the electron-withdrawing group (EWG) weakly conditions the overall outcomes, and conversely a strong influence is unambiguously ascribable to either the N-protected or N-unprotected lactam framework. Specifically, when the NH free substrates (11m-u) are employed, an inversion of the stereochemical control is observed, while the introduction of a Boc protecting group affords the desired product 12v in excellent enantioselectivity (97:3 er).

References

Aug 12, 2005·Chemical Reviews·Jacopo TomasiRoberto Cammi
Mar 31, 2007·Organic Letters·Verena SchulzJean-François Brière
Sep 2, 2009·Ultrasonics Sonochemistry·Anshu DandiaSumit Bhaskaran
Sep 7, 2012·Chemical Reviews·Girija S Singh, Zelalem Y Desta
Jun 15, 2013·Beilstein Journal of Organic Chemistry·Qin Fu, Chao-Guo Yan
Apr 16, 2014·The Journal of Organic Chemistry·Amina BoucherifWen-Jing Xiao
Jun 13, 2014·Angewandte Chemie·Rebecca L DavisKarl Anker Jørgensen
Jul 10, 2014·Chemical Reviews·M Ian ChildersGeoffrey W Coates
May 4, 2017·Chemical Reviews·Christian Ebner, Erick M Carreira
Oct 21, 2017·The Journal of Organic Chemistry·Guo-Li ChaiHenry N C Wong

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Citations

May 3, 2019·The Journal of Organic Chemistry·Christian MertenNora M Kreienborg

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Methods Mentioned

BETA
epoxidation
circular dichroism
NMR

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