ChemInform Abstract: Direct Catalytic Enantio‐ and Diastereoselective Ketone Aldol Reactions of Isocyanoacetates.
0
Citation
1
Reference
10
Related Paper
Abstract:
Abstract A diastereo‐ and enantioselective aldol/cyclization reaction of isocyanate esters with unactivated ketones to yield functionalized oxazolines is developed.Keywords:
Aldol reaction
Isocyanate
Aldol reaction
Aldol condensation
Chiral auxiliary
Cite
Citations (22)
Aldol reaction
Methylene
Aldol condensation
Cite
Citations (31)
Asymmetric organocatalysis have been developed explosively, since the pioneering work on
proline-catalyzed asymmetric direct Aldol reaction reported by List, Barbas and coworkers[1].
Numerous organocatalysts have been designed and the stereochemistry of the Aldol reactions has been
significantly improved. However, organocatalytic direct aldol reactions of aldehydes with long-chain
acyclic aliphatic ketones have been less investigated[2][3]. Herein, we report diamine catalytic aldol
reaction of acyclic aliphatic ketones with aromatic aldehydes, providing high enantioselectivities. In
neat condition, these aldol reactions afforded Aldol products with 80–96% ee.
Aldol reaction
Cite
Citations (0)
Domino
Cite
Citations (51)
A cheap and simple aldol source for the aluminum-enolate in the catalytic aldol-transfer reaction opens a new pathway to prepare aldol adducts of ketones from aldehydes (see picture). The catalytic cycle is completed by the addition of the enolate to an aldehyde and the subsequent aldol exchange reaction with the cheap aldol (regenerates the catalyst).
Aldol reaction
Aldol condensation
Lewis acid catalysis
Cite
Citations (29)
[Chemical reaction: See text] Both matched and mismatched diastereoselections have been observed in the aldol reactions of a range of chiral aldehydes with the dicyclohexylboron enolate of a chiral ethyl ketone related to L-erythrulose. As was previously observed in the corresponding aldol reactions with L-erythrulose derivatives, the Felkin-Anh model provides an adequate explanation for the stereochemical outcome of reactions with chiral alpha-methyl aldehydes. However, a satisfactory account of the results observed with alpha-oxygenated aldehydes was only possible with the Cornforth model. As a practical application of the methodology described herein, a C1-C9 fragment of the structure of the antifungal macrolide soraphen A1alpha has been prepared in a convergent and stereoselective way.
Aldol reaction
Aldol condensation
Cite
Citations (18)
Mannich reaction
Aldol reaction
Hydrocyanation
Cite
Citations (19)
The aldol reaction is one of the most powerful and versatile methods for the construction of C-C bonds. Traditionally, this reaction was developed in a stoichiometric version; however, great efforts in the development of chiral catalysts for aldol reactions were performed in recent years. Thus, in this review article, the development of metal-mediated chiral catalysts in Mukaiyama-type aldol reaction, reductive aldol reaction and direct aldol reaction are discussed. Moreover, the application of these catalysts in the total synthesis of complex molecules is discussed.
Aldol reaction
Stoichiometry
Cite
Citations (24)
The aldol reaction is one of the most important C-C bond forming reactions in organic synthesis, with a large application in the stereoselective synthesis of highly functionalized natural and synthetic substances. The first intermolecular proline-catalyzed direct aldol reaction was described by List and coworkers in 2000. Since then, the direct aldol reaction of aldehydes with ketones in the presence of a catalytic amount of L-proline and its structural derivatives have been evaluated for use in asymmetric catalytic direct aldol reactions. We will report here our preliminary results on the organocatalysts synthesis which will be applied in direct aldol reaction of aldehydes with ketones in aqueous media.
Aldol reaction
Organic Synthesis
Cite
Citations (0)
The enantioselective aldol reaction is among the most useful and well-developed transformations for the synthesis of chiral materials. Despite this, gaps in asymmetric aldol methodology still exist. The authors present the first example of a general, highly enantioselective Mukaiyama aldol reaction between aryl ketones and glyoxylates. An indium-PyBox complex is used as a chiral Lewis acid to induce asymmetry.
Aldol reaction
Lewis acid catalysis
Chiral Lewis acid
Cite
Citations (2)