(−)-Sparteine-Mediated Asymmetric Intramolecular Carbolithiation of Alkenes: Synthesis of Enantiopure Cyclopentanes with Three Consecutive Stereogenic Centers

Hoppe, Dieter; Woltering, Michael J.; Oestreich, Martin; Fröhlich, Roland

doi:10.1002/(sici)1522-2675(19991110)82:11<1860::aid-hlca1860>3.0.co;2-8

Cited by 25 publications

(2 citation statements)

References 19 publications

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“…with three new consecutive stereogenic centers [86]. This method found further application in the synthesis of heterocycles with an indolizidine core [87].…”

Section: Addition To Carbon-carbon Double Bondsmentioning

confidence: 99%

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Non-Deprotonating Methodologies for Organolithium Reagents Starting from Non-Halogenated Materials. Part 2: Transmetallation and Addition to Multiple Bonds

Guijarro¹,

Pastor²,

Yus

2011

COC

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The recent publications on the topic of the preparation of organolithium reagents by non-deprotonating methodologies and starting from non-halogenated substrates have been covered in the present revision. In this second part, transmetallation processes, mainly tin-lithium exchange, and addition to multiple bonds have been considered. Moreover, other procedures, such as carbon-carbon bond scission and the Shapiro reaction, have been included.

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“…with three new consecutive stereogenic centers [86]. This method found further application in the synthesis of heterocycles with an indolizidine core [87].…”

Section: Addition To Carbon-carbon Double Bondsmentioning

confidence: 99%

“…non-4-ene(86) was reported[55]. The carbolithiation of various terminal non-functionalised alkenes (such as propene, isobutene, 1-octene, methylenecyclopentane) was performed with the dianions derived from biphenyl, Reagents and conditions: (i) Bu n Li (1.9 eq), THF, -78 ºC; (ii) H2O; (iii) [Me2N=CH2] + I -, MeCN, reflux; (iv) HCl, MeOH.…”

mentioning

confidence: 99%

Non-Deprotonating Methodologies for Organolithium Reagents Starting from Non-Halogenated Materials. Part 2: Transmetallation and Addition to Multiple Bonds

Guijarro¹,

Pastor²,

Yus

2011

COC

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Asymmetric deprotonation with alkyllithium‐(–)‐sparteine

Hoppe

Christoph

2004

The Chemistry of Organolithium Compounds

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Nonracemic, Chiral Homoenolate Reagents Derived from (Cycloalk-1-enyl)methyl Carbamates and Evaluation of Their Configurational Stabilities

et al. 2002

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Keywords: Asymmetric synthesis / Carbanions / Chirality / LithiationSeveral (cycloalk-1-enyl)methyl N,N-diisopropylcarbamates 11 were synthesised by three different methods and their asymmetric deprotonation by butyllithium/(−)-sparteine was investigated. The ratios of epimeric ion pairs 18·4/epi-18·4 were determined by (stereospecific) trimethylsilylation, forming the products 19/ent-19. Lithiated 2-unsubstituted (cyclopent-1-enyl)methyl carbamates, such as 11a or 11h, epimerise rapidly at −78°C and the thermodynamically controlled ratio is opposite to the kinetically achieved ratio. High configurational stability was found for the 2-methylcycloalk-1-enyl derivatives 11d, 11e and 11j. These turned out to be [a]

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(−)-Sparteine-Mediated Asymmetric Intramolecular Carbolithiation of Alkenes: Synthesis of Enantiopure Cyclopentanes with Three Consecutive Stereogenic Centers

Cited by 25 publications

References 19 publications

Non-Deprotonating Methodologies for Organolithium Reagents Starting from Non-Halogenated Materials. Part 2: Transmetallation and Addition to Multiple Bonds

Non-Deprotonating Methodologies for Organolithium Reagents Starting from Non-Halogenated Materials. Part 2: Transmetallation and Addition to Multiple Bonds

Asymmetric deprotonation with alkyllithium‐(–)‐sparteine

Nonracemic, Chiral Homoenolate Reagents Derived from (Cycloalk-1-enyl)methyl Carbamates and Evaluation of Their Configurational Stabilities

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