Catalyst-Controlled Product Selectivity for Cycloaddition of Bis(indol-3-yl)-allenes to Fused Spiroindolines and Mechanistic Studies

Zhang, Yanyan; Wei, Yin; Shi, Min

doi:10.1021/acs.orglett.9b02992

Cited by 21 publications

(10 citation statements)

References 83 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Bis(indol-3-yl)-allenes 103 can indeed be converted into two different fused spiroindoline products 104 and 105 depending on the metallic complex used to catalyze the reaction (Scheme 27). 59 In the presence of platinum dichloride and tri(pentafluorophenyl)phosphine at 70 °C, indolines 104 are obtained as a mixture of diastereoisomers with yields ranging from 64 to 91%. Dearomative indole addition on the activated allenyl moiety affords the vinyl platinum intermediate int61, which undergoes addition onto the indoleninium to furnish carbenoid int62.…”

Section: Platinum Catalysismentioning

confidence: 99%

Spiroindoles as Intermediates/Products in Transition Metal Catalyzed Dearomatization of Indoles

Buttard

Guinchard

2023

Preprint

View full text Add to dashboard Cite

Spirocyclic indole derivatives are fascinating tridimensional molecular scaffolds, from both a synthetic and biological point of view. Among the diversity of strategies developed to access this kind of structures, transition metal catalysis recently led to impressive advances, especially in order to tame the unique reactivity of the dearomatized spirocyclic intermediates. These species can indeed evolve towards both spirocyclic or non-spirocyclic products through rearomatization-driven processes which are at the same time highly challenging to control but also source of a large structural diversity. This review highlights the most prominent methods of the last decade allowing to trigger a spirocyclization on indole derivatives tethered with a transition metal-activable functional group, leading to both spirocyclic and rearomatized products. The discussion is particularly focused on the reactivity and the complex mechanistic features regarding the evolution of the spiroindoleninium intermediate, highly dependent on the catalytic system.

show abstract

Section: Platinum Catalysismentioning

confidence: 99%

Spiroindoles as Intermediates/Products in Transition Metal Catalyzed Dearomatization of Indoles

Buttard

Guinchard

2023

Preprint

View full text Add to dashboard Cite

show abstract

“…85 In the case of the IPrAuCl/ AgNTf 2 catalytic system, the cyclization reaction of 8a afforded [2 + 2] cycloadducts 8b, while using PtCl 2 as a catalyst led to the involving a catalyst-dependent 1,2-hydride (2°vs 3°C−H) shift from the in situ-generated metal carbene (Scheme 9). 87 In the case of gold catalysis, intramolecular [3 + 2] cycloaddition of bis(indol-3-yl)-allenes 9a afforded the corresponding fused spiroindoline derivatives (cf., 9b) when bulky t BuBrettPho-sAuNTf 2 was employed as a catalyst. Moreover, the asymmetric variant of this reaction was developed by using dinuclear chiral (R)-DTBM-SEGPHOS(AuNTf 2 ) 2 catalyst which provided 9b with good to excellent yields and enantioselectivities.…”

Section: Gold Vs Platinummentioning

confidence: 99%

Divergent Gold Catalysis: Unlocking Molecular Diversity through Catalyst Control

et al. 2021

View full text Add to dashboard Cite

The catalyst-directed divergent synthesis, commonly termed as “divergent catalysis”, has emerged as a promising technique as it allows chartering of structurally distinct products from common substrates simply by modulating the catalyst system. In this regard, gold complexes emerged as powerful catalysts as they offer unique reactivity profiles as compared to various other transition metal catalysts, primarily due to their salient electronic and geometrical features. Owing to the tunable soft π-acidic nature, gold catalysts not only evolved as superior contenders for catalyzing the reactions of alkynes, alkenes, and allenes but also, more intriguingly, have been found to provide divergent reaction pathways over other π-acid catalysts such as Ag, Pt, Pd, Rh, Cu, In, Sc, Hg, Zn, etc. The recent past has witnessed a renaissance in such examples wherein, by choosing gold catalysts over other transition metal catalysts or by fine-tuning the ligands, counteranions or oxidation states of the gold catalyst itself, a complete reactivity switch was observed. However, reviews documenting such examples are sporadic; as a result, most of the reports of this kind remained scattered in the literature, thereby hampering further development of this burgeoning field. By conceptualizing the idea of “Divergent Gold Catalysis (DGC)”, this review aims to consolidate all such reports and provide a unified approach necessary to pave the way for further advancement of this exciting area. Based on the factors governing the divergence in product formation, an explicit classification of DGC has been provided. To gain a fundamental understanding of the divergence in observed reactivities and selectivities, the review is accompanied by mechanistic insights at appropriate places.

show abstract

“…In 2019, Shi and co-workers discovered the asymmetric desymmetrization of bis(indol-3-yl)-allenes with very high regioselectivities and excellent enantioselectivities using ( R )-DTBM-Segphos(AuNTf 2 ) 2 as catalyst. 21 The challenging construction of quaternary carbon stereocenters was achieved via [3 + 2] cycloaddition between allene and indol, which afforded the fused spiroindolines bearing a spiro quaternary stereocenter. In the presence of 2 mol% of t BuBrettphosAuNTf 2 , bis(indol-3-yl)-allenes 15 smoothly furnished a series of fused spiroindolines 16 (Scheme 13).…”

Section: [3 + 2] Cycloadditionsmentioning

confidence: 99%

Gold-catalyzed cycloadditions of allenesviametal carbenes

Gao

Jiang

et al. 2022

Org. Biomol. Chem.

View full text Add to dashboard Cite

show abstract

Catalyst-Controlled Product Selectivity for Cycloaddition of Bis(indol-3-yl)-allenes to Fused Spiroindolines and Mechanistic Studies

Cited by 21 publications

References 83 publications

Spiroindoles as Intermediates/Products in Transition Metal Catalyzed Dearomatization of Indoles

Spiroindoles as Intermediates/Products in Transition Metal Catalyzed Dearomatization of Indoles

Divergent Gold Catalysis: Unlocking Molecular Diversity through Catalyst Control

Gold-catalyzed cycloadditions of allenesviametal carbenes

Contact Info

Product

Resources

About