Enamine-based organocatalysis with proline and diamines: the development of direct catalytic asymmetric Aldol, Mannich, Michael, and Diels-alder reactions.

@article{Notz2004EnaminebasedOW,
  title={Enamine-based organocatalysis with proline and diamines: the development of direct catalytic asymmetric Aldol, Mannich, Michael, and Diels-alder reactions.},
  author={Wolfgang Reinhard Ludwig Notz and Fujie Tanaka and Carlos F. Barbas},
  journal={Accounts of chemical research},
  year={2004},
  volume={37 8},
  pages={
          580-91
        }
}
Enamines and imines have long been recognized as key intermediates in enzyme catalysis, particularly within a class of enzymes organic chemists would very much like to emulate, the aldolases. Here we summarize the contributions of this laboratory to converting enzymatic enamines, and in some cases imines, into a versatile catalytic asymmetric strategy powered by small organic molecules. 
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TLDR
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Additive-controlled regioselective direct asymmetric aldol reaction of hydroxyacetone and aldehyde
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References

SHOWING 1-10 OF 54 REFERENCES
Direct l-Proline-Catalyzed Asymmetric α-Amination of Ketones
The first direct catalytic asymmetric α-amination of ketones catalyzed by l-proline has been developed. The reactions proceed with various azodicarboxylates as the nitrogen source in high yields and
Organocatalysis in Ionic Liquids: Highly Efficient l-Proline-Catalyzed Direct Asymmetric Mannich Reactions Involving Ketone and Aldehyde Nucleophiles
Proline-catalyzed direct asymmetric Mannich reactions of N-PMP protected a-imino ethyl glyoxylate with various alde- hydes and ketones in ionic liquids afforded both a- and b-amino acid derivatives
anti-Selective SMP-catalyzed direct asymmetric Mannich-type reactions: synthesis of functionalized amino acid derivatives
The first (S)-2-methoxymethylpyrrolidine (SMP)-catalyzed direct asymmetric Mannich-type reactions of unmodified aldehydes with N-PMP-protected α-imino ethyl glyoxylate are described. The reaction
Proline-catalyzed one-step asymmetric synthesis of 5-hydroxy-(2E)-hexenal from acetaldehyde.
For the first time, the L-proline-catalyzed direct asymmetric self-aldolization of acetaldehyde is described affording (+)-(5S)-hydroxy-(2E)-hexenal 2 with ee's ranging from 57 to 90%. Further
Origins of opposite absolute stereoselectivities in proline-catalyzed direct Mannich and aldol reactions.
TLDR
The computed transition states provide a general model that explains the origin of the opposite stereoselectivities of proline-catalyzed Mannich and aldol reactions.
Direct organocatalytic asymmetric Mannich-type reactions in aqueous media: one-pot Mannich-allylation reactions
The first direct organocatalytic asymmetric Mannich-type reactions in aqueous media are demonstrated herein. l-Proline-catalyzed reactions in aqueous media to provide β-formyl substituted α-amino
Catalytic direct asymmetric Michael reactions: taming naked aldehyde donors.
[reaction--see text] Direct catalytic enantio- and diastereoselective Michael addition reactions of unmodified aldehydes to nitro olefins using (S)-2-(morpholinomethyl)pyrrolidine as a catalyst are
Catalytic Direct Asymmetric Michael Reactions: Addition of Unmodified Ketone and Aldehyde Donors to Alkylidene Malonates and Nitro Olefins
The Michael additions of a number of ketones and aldehydes to alkylidene malonates and nitro olefins were studied. The reactions employ small organic molecules as catalyst under mild reaction
Catalytic Enantioselective Retro-Aldol Reactions: Kinetic Resolution of β-Hydroxyketones with Aldolase Antibodies.
High enantiomeric enrichment after 50% conversion: Racemates of aldols can be resolved by the title reaction [Eq.(1)] by use of the aldolase antibody 38C2 or 33F12; the ee values of the unconverted
Amine-catalyzed direct self Diels–Alder reactions of α,β-unsaturated ketones in water: synthesis of pro-chiral cyclohexanones
Abstract Amine-catalyzed direct self Diels–Alder reactions of α,β-unsaturated ketones have been developed. ( S )-1-(2-Pyrrolidinyl-methyl)pyrrolidine, l -proline and pyrrolidine catalyzed the
...
1
2
3
4
5
...