Hydrozirconation. II. Oxidative homologation of olefins via carbon monoxide insertion into the carbon-zirconium bond

Bertelo, Christopher A.; Schwartz, Jeffrey

doi:10.1021/ja00834a061

Cited by 103 publications

(28 citation statements)

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“…Early work used [Ni(CO)4], but more recently the reaction has been shown to proceed in the presence of [Ni(CO)2(PPh3)2] and triethylamine. 65 Unfortunately neither of these reactions are catalytic but the homoallylic alcohol method has been used in the synthesis of the sesquiterpene frullanolide (11).65b (42) OR Br a (11) The conversion of hydroxy-substituted vinyl halides into a-methylenebutyrolactones can be performed catalytically in the presence of [Pd(PPh3)4]. 66 The starting materials for this reaction are prepared from epoxides and a-silylated vinyl Grignard reagents followed by the substitution of the silyl substituent by bromine.…”

Section: R~2mentioning

confidence: 99%

Carbonylation and Decarbonylation Reactions

Thompson¹

1991

Comprehensive Organic Synthesis

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Section: R~2mentioning

confidence: 99%

Carbonylation and Decarbonylation Reactions

Thompson¹

1991

Comprehensive Organic Synthesis

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“…Similarly, oxidation with bromine in methanol returned the methyl ester 28. [6] Acylzirconocenes are among the most synthetically useful acyl anion equivalents. They are partners in various C-C bond forming reactions and precursors to diverse carbonyl compounds.…”

Section: Introductionmentioning

confidence: 99%

“…((Please delete this text if not appropriate)) [2,3,4,5] Among the most useful transformations of organozirconocenes is their carbonylation to yield acyl zirconium complexes. [6] These reagents serve as acyl anion equivalents and can undergo oxidation to yield carboxylic acid derivatives and react in C-C bond forming processes to yield unsymmetrical ketones. For example, acyl zirconium reagents add to ketones and enones to form α-hydroxy ketones and 1,4-diketones, respectively.…”

mentioning

confidence: 99%

Zirconocene‐Mediated Carbonylative Coupling of Grignard Reagents

2016

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Organozirconocenes are versatile synthetic intermediates that can undergo carbonylation to yield acyl anion equivalents. Zirconocene hydrochloride (Cp 2 ZrHCl) is often the reagent of choice for accessing these intermediates but generates organozirconocenes only from alkenes and alkynes. This requirement eliminates a broad range of substrates including aromatic rings, benzylic groups, and alkyl groups that possess a tertiary or quaternary carbon alpha to the carbon-zirconium bond. To provide more generalized access to acyl zirconium reagents, we explored transmetalation of Grignard reagents with zirconocene dichloride under a CO atmosphere. This protocol generates acyl zirconium (IV) complexes that are inaccessible using the Schwartz reagent, including those derived from secondary and tertiary alkyl and aryl Grignard reagents. Graphical AbstractAcyl zirconocenes [Cp 2 ZrCl(COR)] are valuable acyl anion equivalents in synthetic chemistry. Traditionally, they have been prepared through hydrozirconation of olefins or alkynes, precluding generation of aryl, benzyl, tertiary alkyl or branched acyl zirconocenes. Here we describe a Zrmediated carbonylative coupling of Grignard reagents that involves previously inaccessible zirconocene intermediates.Correspondence to: Joseph M. Ready, joseph.ready@utsouthwestern.edu. Supporting information for this article is given via a link at the end of the document.((Please delete this text if not appropriate)) [2,3,4,5] Among the most useful transformations of organozirconocenes is their carbonylation to yield acyl zirconium complexes. [6] These reagents serve as acyl anion equivalents and can undergo oxidation to yield carboxylic acid derivatives and react in C-C bond forming processes to yield unsymmetrical ketones. For example, acyl zirconium reagents add to ketones and enones to form α-hydroxy ketones and 1,4-diketones, respectively. [7] Additionally, they couple with aryl and allyl electrophiles under metalmediated conditions. [8,9,10] Enantio-selective transformations of acyl zirconocenes have been developed to generate optically active ketone derivatives. [11] Organozirconium reagents are generally prepared by hydrozirconation of olefins or alkynes. These hydrometalations are highly regioselective, generally providing the less hindered alkyl or vinyl zirconium intermediate. [12] Indeed, hydrozirconation of internal olefins usually forms the terminal alkyl complex product through an isomerization sequence involving reversible hydrozirconation/β-hydride elimination (Scheme 1). [1] Additionally, hydrozirconation necessarily results in a zirconium complex with a β-C-H bond. This requirement excludes broad substrate classes including aryl and benzyl zirconium complexes. We sought to expand the scope of available organozirconium reagents through transmetalation from readily available organometallic species. While unprecedented, such a process could yield zirconium reagents that are currently inaccessible through hydrozirconation, including aryl-benzyl-and tertiary and sec...

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Abstract: In the presence of 1,1,1,3,3,1,1,3,3, HFIP), isoquinolines react with acylzirconocene chlorides to give N-acyl adductsw ith incorporation of ap roton at the C-1 position. Thep resent procedure could be applied to the reactiono fq uinolines.

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mentioning

confidence: 99%

“…[1] We have studied on the use of these complexes as ad onor of the unmasked acyl anion in organic syntheses. [2,3] Since the functionalized nitrogen heterocycles are importants ynthetic intermediates and structural units of alkaloids and biologically active compounds, [4] we recently developed a Reissert-type acylation reactiono fa zaaromatic compounds such as isoquinolines andquinolines with acylzirconocene chloridesu nder Cu-catalyzed conditions, that is,the nucleophilic C-acylation of N-acylisoquinolinium and -quinolinium ions generated from azaaromatic compoundsa nd chloroformates as acylating agents (Scheme 1a).…”

mentioning

confidence: 99%

Formal N‐Acylation Reaction of Azaaromatics with Acylzirconocene Chloride Complexes and 1,1,1,3,3,3‐Hexafluoro‐2‐propanol

et al. 2015

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In the presence of 1,1,1,3,3,1,1,3,3, HFIP), isoquinolines react with acylzirconocene chlorides to give N-acyl adductsw ith incorporation of ap roton at the C-1 position. Thep resent procedure could be applied to the reactiono fq uinolines. Theser eactions provide us with an alternative method for the Reissert-type reduction reactions of azaaromatics with N-acylating reagents andr educing reagents.

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Hydrozirconation. II. Oxidative homologation of olefins via carbon monoxide insertion into the carbon-zirconium bond

Cited by 103 publications

References 1 publication

Carbonylation and Decarbonylation Reactions

Carbonylation and Decarbonylation Reactions

Zirconocene‐Mediated Carbonylative Coupling of Grignard Reagents

Formal N‐Acylation Reaction of Azaaromatics with Acylzirconocene Chloride Complexes and 1,1,1,3,3,3‐Hexafluoro‐2‐propanol

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