Highly Stereoselective and Scalableanti-Aldol Reactions UsingN-(p-Dodecylphenylsulfonyl)-2-pyrrolidinecarboxamide: Scope and Origins of Stereoselectivities

Ye, Hua; Mahapatra, Subham; Cheong, Paul Ha‐Yeon; Carter, Rich G.

doi:10.1021/jo1015008

Cited by 75 publications

(26 citation statements)

References 139 publications

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“…However, aldol asymmetric reaction of bulkier aldehyde derivatives with ketones has rarely been considered in literature . A deep clarification of these issues is important not only to perceive the various influencing factors of the aldol reaction, but also to establish a new methodology applicable to a wider range of substrates under optimal conditions . Accordingly, our current research mostly focused on expanding the substrate scope of the asymmetric aldol reaction, and therefore the suitable aromatic aldehydes were further derived into the bulkier derivatives, such as 2‐naphthaldehyde, 9‐anthracenecarboxaldehyde, and 1‐pyrenecarboxaldehyde.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Extended Bipyridine‐proline Chiral Catalysts and Resulting Effects on the Asymmetric Aldol Reactions of Bulkier Aldehyde Derivatives with Cyclohexanone

Sun

Bai

et al. 2020

ChemistrySelect

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Axially‐unfixed 2,2′‐bipyridine‐based chiral catalysts were synthesized using enantiopure amino acids as chiral sources, which were successfully used in asymmetric aldol reactions of p‐nitrobenzaldehyde with cyclohexanone, while the bulkier aldehyde derivatives (2‐naphthaldehyde, 9‐anthracenecarboxaldehyde, and 1‐pyrenecarboxaldehyde) were selected to further elucidate the catalytic properties. Particularly, the influences of the bipyridine‐proline chiral structures and the polarities of used solvents (petroleum ether, toluene, CH2Cl2, ethanol, DMF, DMSO, and water) on the catalytic performance were investigated. The results indicated that the structure of bipyridine catalysts, the molecular volume of aldehydes, and the polarity of solvents have significant eﬀects on the catalytic activities, in which, the smaller steric effects were conducive to the improvement of the yields and stereoselectivities for asymmetric aldol reaction, along with the increased polarity of used solvents and the decreased molecular volume of aldehydes. Meanwhile, the chemical identity of all compounds was confirmed by 1H‐NMR, 13C‐NMR, HRMS, and HPLC analysis.

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Section: Introductionmentioning

confidence: 99%

Synthesis of Extended Bipyridine‐proline Chiral Catalysts and Resulting Effects on the Asymmetric Aldol Reactions of Bulkier Aldehyde Derivatives with Cyclohexanone

Sun

Bai

et al. 2020

ChemistrySelect

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“…2.5 , indicated by thin lines, Figure 2). [13] In the disfavored (R)-TSs, this stabilizing electrostatic contact is replaced by a repulsive electrostatic interaction between a methylene and the b-nitrostyrene benzylic hydrogen. This enthalpic preference is worth 0.5 and 1 kcal mol À1 for unsubstituted furan and pyran substrates (TS-I and TS-II), respectively.…”

Section: Resultsmentioning

confidence: 99%

“…Characterization and supporting information for previously published compounds: Full characterization of compounds of type 6, 14 and 15 (Scheme 4) as well as copies of 1 H NMR spectra, 13 C NMR spectra, and HPLC chromatograms is contained in the Supporting Information for reference [6].…”

Section: Methodsmentioning

confidence: 99%

Organocatalytic Kinetic Resolution Cascade Reactions: New Mechanistic and Stereochemical Manifold in Diphenyl Prolinol Silyl Ether Catalysis

McGarraugh

Johnston

Martínez‐Muñoz

et al. 2012

Chemistry A European J

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A new cascade reaction involving an iminium-catalyzed intramolecular oxa-Michael addition followed by an enamine-catalyzed intermolecular Michael addition is reported herein. This cascade reaction generates enantiopure, highly functionalized tetrahydropyrans and tetrahydrofurans in a one-pot reaction and in up to 89 % combined yield and up to 99 % ee. This cascade reaction is catalyzed by diaryl prolinol silyl ethers, which are a privileged class of catalysts. The stereochemical outcome of these cascade reactions is unprecedented. Computational studies indicate that this stereochemical outcome arises from nonclassical hydrogen-bonding interactions between the electrophile and the substrate, and from entropic considerations of preorganization. The unprecedented configurations of the cascade products, combined with the computational models, reveal for the first time that asymmetric induction by diaryl prolinol silyl ether catalysts is not always exclusively reagent controlled. The stereochemical outcome also arises from a kinetic resolution or dynamic kinetic resolution of the β-stereocenter through an enamine-catalyzed intermolecular reaction. This unprecedented organocascade reaction mechanism may be adaptable to diaryl prolinol silyl ether-catalyzed cascade reactions, in which both the iminium- and enamine-catalyzed steps are intermolecular, an underdeveloped type of cascade reaction.

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“…[14][15][16] Ionic liquids used as solvents were prepared as already described. Analytical-and HPLC-grade solvents for workup and purification procedures and HPLC analysis were purchased from commercial suppliers and used as received.…”

Section: Methodsmentioning

confidence: 99%

Asymmetric Michael Addition Induced by the Anion of an Imidazolium Salt

Gauchot¹,

Gravel²,

Schmitzer³

2012

Eur J Org Chem

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Highly Stereoselective and Scalableanti-Aldol Reactions UsingN-(p-Dodecylphenylsulfonyl)-2-pyrrolidinecarboxamide: Scope and Origins of Stereoselectivities

Cited by 75 publications

References 139 publications

Synthesis of Extended Bipyridine‐proline Chiral Catalysts and Resulting Effects on the Asymmetric Aldol Reactions of Bulkier Aldehyde Derivatives with Cyclohexanone

Synthesis of Extended Bipyridine‐proline Chiral Catalysts and Resulting Effects on the Asymmetric Aldol Reactions of Bulkier Aldehyde Derivatives with Cyclohexanone

Organocatalytic Kinetic Resolution Cascade Reactions: New Mechanistic and Stereochemical Manifold in Diphenyl Prolinol Silyl Ether Catalysis

Asymmetric Michael Addition Induced by the Anion of an Imidazolium Salt

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