Metalation of 9‐Oxabicyclo[3.3.1]nonadiene – the Deprotonation Path to Bridgehead Olefins

Bassioni, Ghada; Köhler, Frank H.

doi:10.1002/ejoc.200600099

Cited by 5 publications

(2 citation statements)

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“…54 Directed lithiation A new route to bridgehead alkenes based on a deprotonation reaction has been established. 55 The deprotonation of 9-oxabicyclo[3.3.1]nonadiene (10) with t-BuLi-TMEDA occurs selectively in the allylic position. While (10) has four allyl positions, only one bridgehead proton is removed, as demonstrated by quenching with Me 3 SnCl, Me 3 SiOTf, and Me 3 PbCl (Scheme 6).…”

Section: Organometallic Speciesmentioning

confidence: 99%

Carbanions and Electrophilic Aliphatic Substitution

Birsa

2010

Organic Reaction Mechanisms · 2006

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Section: Organometallic Speciesmentioning

confidence: 99%

Carbanions and Electrophilic Aliphatic Substitution

Birsa

2010

Organic Reaction Mechanisms · 2006

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“…The lithiation of 9-oxabicyclo[3.3.1]nona-2,6-diene (7) with t-BuLi-TMEDA is the only example for a deprotonation of an oxygen-bridged bicyclic compound. 17,18 This process, however, is facilitated by the formation of a stabilized allyl anion intermediate, as obvious from the regioisomeric products 8A and 8B obtained upon addition of an electrophile. 17 In this letter we report on the deprotonation of the 9-oxabispidines 3 and 4 with s-BuLi at -78°C leading to stable a-lithio ethers that were trapped with electrophiles in…”

Section: Figurementioning

confidence: 99%

Thieme Chemistry Journal Awardees - Where Are They Now? Bridgehead Lithiated 9-Oxabispidines

Breuning¹,

Steiner²,

Hein³

et al. 2009

Synlett

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Iron(II) Chloride‐Catalyzed Nitrene Transfer Reaction for Dearomative Amination of β‐Naphthols with Aryl Azides

Guan

Peng

et al. 2018

Adv Synth Catal

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A first example of Fe-catalyzed dearomative amination of b-naphthols with aryl azides is described. The method constructs a nitrogen-containing quaternary carbon center catalyzed by cheap and readily available iron salt FeCl 2 , and affords a series of a-amino-b-naphthalenones in good to excellent yields under simple and mild reaction conditions. Preliminary experimental and computational studies suggest that the reaction is probably initiated by iron-iminyl diradical and followed by intramolecular hydrogen transfer to generate iron-aminyl radical and finally an intramolecular radical combination reaction.Nitrogen is one of the most important elements in natural products and bioactive compounds. Thus, many efforts have been put into the development of efficient synthetic approaches to nitrogen-containing organic compounds. Among them, transition-metalcatalyzed nitrene transfer reaction with azides as precursors is regarded as one of the most efficient and atom-economic tools for the synthesis of nitrogencontaining moleculars. [1] However, only a few kind of efficient nitrene transfer reactions such as CÀH bond amination, [2] aziridination of olefins, [3] and sulfur imidations [4] were developed (Scheme 1). Hence, exploring the applications of such reactions in other type of transformations to overcome some difficult targets like constructing of nitrogen-containing quaternary carbon center [5] is an interesting but still challenging objective.Generally, in first row transition metal catalyzed nitrene transfer reactions, metal imido species, proved as the key active intermediate, has been confirmed to have significant radical character. [6][7][8] For instance, recent advances in the iron-catalyzed C-H amination reaction [7, 8] have demonstrated that the mechanism involves a hydrogen atom abstraction (HAA) from C-H bonds by iron-imido species followed by radical rebound [9] to the iron-amido moiety on basis of a number of theoretical and experimental evidences. We postulated that if a metal imido species abstracts a hydrogen from OÀH bond of enolate to form an enolate radical which could isomer to a-carbonyl radical, [10] the a-carbonyl radical could couple with the newly formed iron-aminyl radical, and would therefore offer a valuable method for constructing CÀN bond. Herein, we report the first successful example Scheme 1. The types of metal catalyzed nitrene transfer reactions.

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Metalation of 9‐Oxabicyclo[3.3.1]nonadiene – the Deprotonation Path to Bridgehead Olefins

Cited by 5 publications

References 60 publications

Carbanions and Electrophilic Aliphatic Substitution

Carbanions and Electrophilic Aliphatic Substitution

Thieme Chemistry Journal Awardees - Where Are They Now? Bridgehead Lithiated 9-Oxabispidines

Iron(II) Chloride‐Catalyzed Nitrene Transfer Reaction for Dearomative Amination of β‐Naphthols with Aryl Azides

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