Phosphine catalysed (5 + 1) annulation of ynone/cinnamates with primary amines

Ametovski, Jhi; Dutta, Uttam; Burchill, Laura; Lupton, David W.; Hooper, Joel F.

doi:10.1039/c7cc08252e

Cited by 13 publications

(13 citation statements)

References 56 publications

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“…In 2017, Hooper, Lupton et al reported a [5 + 1] annulation of ynone/Michael acceptors with sulfonamides, affording isoquinolones, pyrrolidinones, and pyrrolopiperazines (Scheme 442). 516 Variations of the sulfonamide partner, the β -substituent of the ynone, the Michael acceptor, and the linker could be tolerated, with the desired products obtained in moderate to good yields and with good Z / E ratios. Nevertheless, use of an aliphatic linker and a pyrrole linker resulted in moderate yields.…”

Section: Nucleophilic Phosphine Catalysis Of Acetylenesmentioning

confidence: 99%

Phosphine Organocatalysis

et al. 2018

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The hallmark of nucleophilic phosphine catalysis is the initial nucleophilic addition of a phosphine to an electrophilic starting material, producing a reactive zwitterionic intermediate, generally under mild conditions. In this Review, we classify nucleophilic phosphine catalysis reactions in terms of their electrophilic components. In the majority of cases, these electrophiles possess carbon–carbon multiple bonds: alkenes (section 2), allenes (section 3), alkynes (section 4), and Morita–Baylis–Hillman (MBH) alcohol derivatives (MBHADs; section 5). Within each of these sections, the reactions are compiled based on the nature of the second starting material—nucleophiles, dinucleophiles, electrophiles, and electrophile–nucleophiles. Nucleophilic phosphine catalysis reactions that occur via the initial addition to starting materials that do not possess carbon–carbon multiple bonds are collated in section 6. Although not catalytic in the phosphine, the formation of ylides through the nucleophilic addition of phosphines to carbon–carbon multiple bond–containing compounds is intimately related to the catalysis and is discussed in section 7. Finally, section 8 compiles miscellaneous topics, including annulations of the Hüisgen zwitterion, phosphine-mediated reductions, iminophosphorane organocatalysis, and catalytic variants of classical phosphine oxide–generating reactions.

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Section: Nucleophilic Phosphine Catalysis Of Acetylenesmentioning

confidence: 99%

Phosphine Organocatalysis

et al. 2018

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“…[2][3][4] While synthesis by stoichiometric generation of homoenolates has received attention for more than 50 years, [2] catalytic approaches have appeared more intermittently. [3,4] As part of ongoing studies on the umpolung of conjugate acceptors, [5,6] herein we report N-heterocyclic carbene (NHC) catalyzed [7] all-carbon (5+ +1) annulations by ah itherto unreported vinyl dianion synthon strategy.S pecifically, b-unsubstituted conjugate acceptors undergo homoenolate formation twice and couple to fivecarbon bis(electrophile)s to provide mono-and bicyclic cyclohexanones.T he reaction has been realized with inter-and intramolecular designs,a nd in some cases,w ith high levels of enantioselectivity.…”

Section: Introductionmentioning

confidence: 99%

“…Alternately,iftwo of the three electrophiles are tethered then an intermolecular (5+ +1) reaction [Eq. (6)],i nvolving dimerization and cycloisomerization, should give cyclohexanones (i.e. 16).…”

Section: Introductionmentioning

confidence: 99%

N‐Heterocyclic Carbene Catalyzed (5+1) Annulations Exploiting a Vinyl Dianion Synthon Strategy

et al. 2019

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Direct polarity inversion of conjugate acceptors provides av aluable entry to homoenolates.N -heterocyclic carbene (NHC) catalyzedr eactions,i nw hich b-unsubstituted conjugate acceptors undergo homoenolate formation and C À C bond formation twice,h ave been developed. Specifically,t he all-carbon (5+ +1) annulations give ar ange of mono-and bicyclic cyclohexanones (31 examples). In the first family of annulations, b-unsubstituted acrylates tethered to ad ivinyl ketone undergo cycloisomerization, providing hexahydroindenes and tetralins.I nt he second, partially untethered substrates undergo an intermolecular (5+ +1) annulation involving dimerization followed by cycloisomerization. While enantioselectivity was not possible with the former,t he latter proved viable,a llowing cyclohexanones to be produced with high levels of enantiopurity (most > 95:5 e.r.)a nd exclusive diastereoselectivity (> 20:1 d.r.). Derivatizations and mechanistic studies are also reported. Scheme 1. Backgrounda nd mechanistic framework. EWG = electronwithdrawinggroup.Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

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“…[2][3][4] While synthesis via stoichiometric generation of homoenolates has received attention for more than 50-years, [2] catalytic approaches have appeared more intermittently. [3,4] As part of ongoing studies on the umpolung of conjugate acceptors, [5,6] herein we report NHC-catalyzed [7] all-carbon (5 + 1) annulations via a hitherto unreported vinyl dianion synthon strategy. Specifically, unsubstituted conjugate acceptors undergo homoenolate formation twice and couple to 5-carbon bis-electrophiles to provide mono and bicyclic cyclohexanones.…”

Section: Introductionmentioning

confidence: 99%

N‐Heterocyclic Carbene Catalyzed (5+1) Annulations Exploiting a Vinyl Dianion Synthon Strategy

et al. 2019

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Direct polarity inversion of conjugate acceptors provides a valuable entry to homoenolates. N‐heterocyclic carbene (NHC) catalyzed reactions, in which β‐unsubstituted conjugate acceptors undergo homoenolate formation and C−C bond formation twice, have been developed. Specifically, the all‐carbon (5+1) annulations give a range of mono‐ and bicyclic cyclohexanones (31 examples). In the first family of annulations, β‐unsubstituted acrylates tethered to a divinyl ketone undergo cycloisomerization, providing hexahydroindenes and tetralins. In the second, partially untethered substrates undergo an intermolecular (5+1) annulation involving dimerization followed by cycloisomerization. While enantioselectivity was not possible with the former, the latter proved viable, allowing cyclohexanones to be produced with high levels of enantiopurity (most >95:5 e.r.) and exclusive diastereoselectivity (>20:1 d.r.). Derivatizations and mechanistic studies are also reported.

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Phosphine catalysed (5 + 1) annulation of ynone/cinnamates with primary amines

Cited by 13 publications

References 56 publications

Phosphine Organocatalysis

Phosphine Organocatalysis

N‐Heterocyclic Carbene Catalyzed (5+1) Annulations Exploiting a Vinyl Dianion Synthon Strategy

N‐Heterocyclic Carbene Catalyzed (5+1) Annulations Exploiting a Vinyl Dianion Synthon Strategy

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