HMPA Promotes Retro-Aldol Reaction, Resulting in Syn-Selective Addition of Lithiated 1-Naphthylacetonitrile to Aromatic Aldehydes

2000 ◽  
Vol 2 (16) ◽  
pp. 2443-2445 ◽  
Author(s):  
Paul R. Carlier ◽  
Cedric W.-S. Lo ◽  
Michael M.-C. Lo ◽  
Nan Chi Wan ◽  
Ian D. Williams
Keyword(s):  
Aldol Reaction ◽  
Aromatic Aldehydes ◽  
Selective Addition

ChemInform Abstract: HMPA Promotes retro-Aldol Reaction, Resulting in syn-Selective Addition of Lithiated 1-Naphthylacetonitrile to Aromatic Aldehydes.

ChemInform ◽  
2000 ◽  
Vol 31 (43) ◽  
pp. no-no
Author(s):  
Paul R. Carlier ◽  
Cedric W.-S. Lo ◽  
Michael M.-C. Lo ◽  
Nan Chi Wan ◽  
Ian D. Williams
Keyword(s):  
Aldol Reaction ◽  
Aromatic Aldehydes ◽  
Selective Addition

Formal Total Syntheses of Crocacin A-D

2005 ◽  
Vol 70 (10) ◽  
pp. 1696-1708 ◽  
Author(s):  
Magnus Besev ◽  
Christof Brehm ◽  
Alois Fürstner
Keyword(s):  
Natural Products ◽  
Aldol Reaction ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Total Syntheses ◽  
Cross Coupling Reactions ◽  
Palladium Catalyzed ◽  
The Common ◽  
Selective Addition

A concise route to the common polyketide fragment5of crocacin A-D (1-4) is presented which has previously been converted into all members of this fungicidal and cytotoxic family of dipeptidic natural products by various means. Our synthesis features asyn-selective titanium aldol reaction controlled by a valinol-derived auxiliary, a zinc-mediated, palladium-catalyzedanti-selective addition of propargyl mesylate10to the chiral aldehyde9, as well as a comparison of palladium-catalyzed Stille and Suzuki cross-coupling reactions for the formation of the diene moiety of the target.

(S,S,S)-Perhydroindolic Acid: Efficient Catalyst for Direct Asymmetric Aldol Reaction from Aromatic Aldehydes.

ChemInform ◽  
2007 ◽  
Vol 38 (3) ◽  
Author(s):  
Xiaoping Tang ◽  
Benoit Liegault ◽  
Jean-Luc Renaud ◽  
Christian Bruneau
Keyword(s):  
Aldol Reaction ◽  
Aromatic Aldehydes ◽  
Efficient Catalyst ◽  
Asymmetric Aldol ◽  
Asymmetric Aldol Reaction

ChemInform Abstract: Highly Enantioselective Proline-Catalyzed Direct Aldol Reaction of Chloroacetone and Aromatic Aldehydes.

ChemInform ◽  
2012 ◽  
Vol 43 (37) ◽  
pp. no-no
Author(s):  
Angel Martinez-Castaneda ◽  
Belen Poladura ◽  
Humberto Rodriguez-Solla ◽  
Carmen Concellon ◽  
Vicente del Amo
Keyword(s):  
Aldol Reaction ◽  
Aromatic Aldehydes ◽  
Direct Aldol Reaction

Highly Enantioselective Proline-Catalysed Direct Aldol Reaction of Chloroacetone and Aromatic Aldehydes

2012 ◽  
Vol 18 (17) ◽  
pp. 5188-5190 ◽  
Author(s):  
Ángel Martínez-Castañeda ◽  
Belén Poladura ◽  
Humberto Rodríguez-Solla ◽  
Carmen Concellón ◽  
Vicente del Amo
Keyword(s):  
Aldol Reaction ◽  
Aromatic Aldehydes ◽  
Direct Aldol Reaction

scholarly journals Bioinspired Polymer-Bound Organocatalysts for Direct Asymmetric Aldol Reaction: Experimental and Computational Studies

Catalysts ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 398
Author(s):  
Ganhong Du ◽  
Jun Ling ◽  
Fangyu Hu ◽  
Keyuan Liu ◽  
Long Ye ◽  
...  
Keyword(s):  
Theoretical Calculations ◽  
Aldol Reaction ◽  
Catalytic Efficiency ◽  
Aromatic Aldehydes ◽  
Relative Energy ◽  
Catalyst Loading ◽  
Polymer Backbone ◽  
Asymmetric Aldol ◽  
Tertiary Amide ◽  
Asymmetric Aldol Reaction

A series of poly(2-oxazoline) (POX) derivatives bearing prolinamide pendants were designed as organocatalysts and evaluated in the direct asymmetric aldol reaction between aromatic aldehydes and cyclic ketones. The structural variation of the alkyl spacer connecting the polymer backbone with the catalytic unit was applied so as to deduce structure–performance relationships combined with comparable experiments from model catalysts. Results showed that the POX-bound prolinamides can promote the aldol reaction more effectively as compared to their small-molecular and non-POX-bound analogs. The catalyst P3 containing the pyrrolidine moiety closer to the tertiary amide backbone exhibited the overall best catalytic efficiency, affording anti-products in 84% yield with 89% ee in the representative aldol addition of cyclohexanone to 4-nitrobenzaldehyde at a 10 mol.% catalyst loading. Furthermore, the influence of trifluoroacetic acid as an additive on the asymmetric transformation was investigated. Theoretical calculations revealed that the protonation of the aldehyde carbonyl group switched the activation mode of the aldol acceptor through hydrogen bond interactions, thereby changing the relative energy barrier of the enamine/aldehyde reaction transition states, which accounted well for the significant improvement in the enantioselectivity of the acidic additives observed experimentally.

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