Recent advances in the Stevens rearrangement of ammonium ylides. Application to the synthesis of alkaloid natural products

Vanecko, John A.; Wan, Hayley; West, F. G.

doi:10.1016/j.tet.2005.09.123

Cited by 178 publications

(112 citation statements)

References 93 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Indeed, Stevens and co-workers described that, in the presence of a strong base, quaternary ammonium salts may undergo a 1,2-rearrangement. This reaction, commonly referred to as the Stevens rearrangement, [53][54][55] results in the formation of a tertiary amine which at basic conditions is neutral. Thus, the electrostatic forces binding the IrO 2 /PDDA bilayers together weaken or disappear with time under alkaline conditions, leading to a terminal loss of film stability and gradual removal of catalytic IrO 2 NPs from the surface of the FTO electrode.…”

mentioning

confidence: 99%

Boosting water oxidation layer-by-layer

Hidalgo-Acosta

Scanlon

Méndez

et al. 2016

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

), moving from acidic to alkaline conditions. Bulk electrolysis experiments revealed that the IrO 2 /PDDA films were stable and adherent under acidic and neutral conditions but degraded in alkaline solutions. Oxygen was evolved with Faradaic efficiencies approaching 100% under acidic (pH 1) and neutral (pH 7) conditions, and 88% in alkaline solutions (pH 13).This layer-by-layer approach forms the basis of future large-scale OER electrode development using ink-jet printing technology.

show abstract

mentioning

confidence: 99%

Boosting water oxidation layer-by-layer

Hidalgo-Acosta

Scanlon

Méndez

et al. 2016

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

show abstract

“…A metalfree carbene approach to derivatize brucine was recently reported, which yielded a ring-expanded product through formation of an aza-ylide species followed by a [1,2]-Stevens rearrangement 34 . Indeed, the use of metallocarbenoids to access an aza-ylide intermediate followed by ring expansion has been widely described [35][36][37] . Interested in effecting C-H insertions via a carbenoid approach, we were intrigued as to whether the presence of a suitable rhodium catalyst and appropriate temperature might influence the nature of the reaction with brucine, allowing for C-H insertion over aza-ylide formation or catalyst poisoning, despite the presence of the nucleophilic amine.…”

Section: Resultsmentioning

confidence: 99%

Late-stage C–H functionalization of complex alkaloids and drug molecules via intermolecular rhodium-carbenoid insertion

et al. 2015

View full text Add to dashboard Cite

Alkaloids constitute a large family of natural products possessing diverse biological properties. Their unique and complex structures have inspired numerous innovations in synthetic chemistry. In the realm of late-stage C-H functionalization, alkaloids remain a significant challenge due to the presence of the basic amine and a variety of other functional groups. Herein we report the first examples of dirhodium(II)-catalysed intermolecular C-H insertion into complex natural products containing nucleophilic tertiary amines to generate a C-C bond. The application to a diverse range of alkaloids and drug molecules demonstrates remarkable chemoselectivity and predictable regioselectivity. The capacity for late-stage diversification is highlighted in the catalyst-controlled selective functionalizations of the alkaloid brucine. The remarkable selectivity observed, particularly for site-specific C-H insertion at N-methyl functionalities, offers utility in a range of applications where efficient installation of synthetic handles on complex alkaloids is desired.

show abstract

“…We first explored the Stevens rearrangement 6 of the preformed iminium 8 co-catalyzed by ionic liquid. It was suggested that ionic liquids can activate and stabilize zwiterionic species in solution.…”

Section: Resultsmentioning

confidence: 99%

Studies towards the construction of quaternary indolizidines by [2,3]-sigmatropic rearrangement cocatalyzed by ionic liquid

Durán-Lara¹,

Shankaraiah²,

Geraldo³

et al. 2009

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

Uma abordagem enantiosseletiva eficiente para a preparação de centros quaternários a partir da prolina 5 foi desenvolvida através do rearranjo [2,3]-sigmatrópico de Stevens, co-catalisado por líquido iônico. O rearranjo sigmatrópico foi estereoespecífico porque as migrações- [2,3] foram restritas à mesma face e a estereosseletividade surgiu na etapa preliminar da N-alquilação em 8. O método mostrou melhores rendimentos do que os descritos na literatura. O uso de hexafluorofostato de 1-butil-3-metilimidazólio mostrou uma melhora nos rendimentos do rearranjo de Stevens devido a possível estabilização e/ou ativação das espécies zuiteriônicas em solução, pelo líquido iônico. Diversas indolizidinas foram sintetizadas a partir do derivado (S)-5 da prolina quaternária.An efficient enantioselective approach for preparation of quaternary centers from proline 5 building block has been developed through [2,3]-sigmatropic Stevens rearrangement co-catalyzed by ionic liquid. The sigmatropic rearrangement was stereospecific because the [2,3]-migrations were restricted to the same face, and the stereoselectivity arose from the previous N-alkylation step in 8. The approach showed better yields than described in literature. The use of 1-butyl-3-methylimidazolium hexafluorophosphate showed an improvement in the yields of the Stevens rearrangement due to a possible stabilization and/or activatation of zwiterionic species in solution by the ionic liquid. Several indolizidine moieties were synthesized from quaternary proline derivative (S)-5.

show abstract

Recent advances in the Stevens rearrangement of ammonium ylides. Application to the synthesis of alkaloid natural products

Cited by 178 publications

References 93 publications

Boosting water oxidation layer-by-layer

Boosting water oxidation layer-by-layer

Late-stage C–H functionalization of complex alkaloids and drug molecules via intermolecular rhodium-carbenoid insertion

Studies towards the construction of quaternary indolizidines by [2,3]-sigmatropic rearrangement cocatalyzed by ionic liquid

Contact Info

Product

Resources

About