Reference EntryDOI
The Catalyzed α‐Hydroxyalkylation and α‐Aminoalkylation of Activated Olefins (The Morita—Baylis—Hillman Reaction)
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TLDR
The Baylis-Hillman reaction was first reported by Morita and Hillman as discussed by the authors, who reported the reaction of acetaldehyde with ethyl acrylate and acrylonitrile in the presence of catalytic amounts of 1,4-diazabicyclo[2.2] octane to give the α-hydroxyethylated products in good yields.Abstract:
In a patent application published in 1972, Baylis and Hillman reported the reaction of acetaldehyde with ethyl acrylate and acrylonitrile in the presence of catalytic amounts of 1,4-diazabicyclo[2.2.2]octane to give the α-hydroxyethylated products in good yields. No structure proof was given. The assignment eventually was shown to be correct, but since the initial disclosure was not followed by a journal publication, this remarkably simple, atom-efficient, and useful reaction was ignored for a number of years, and it has been only fairly recently that its potential has begun to be explored. The transformation is now commonly referred to as the Baylis–Hillman reaction. This is unfortunate because credit for its invention clearly belongs to Morita, who five years earlier, in patents and a brief paper reported the same reaction with the exception that tertiary phosphines were used as the catalysts; he also proposed the currently accepted mechanism. Baylis and Hillman made reference to Morita's work in their patent application. It is true that tertiary amines in general are cheaper, less toxic, and more readily removed than tertiary phosphines. However, the latter sometimes give higher yields in shorter reaction times, and there are a number of examples where they are the only useful catalysts.
The DABCO-catalyzed reaction is slow, and reaction times at room temperature of days or even weeks are common. Attempts to remedy this situation by use of other amine catalysts, change of reaction temperature, high pressure, or microwave irradiation have been partially successful. Activated olefins other than acrylonitrile and acrylic esters that have now been shown to undergo the reaction include α,β-unsaturated aldehydes and ketones, vinyl sulfoxides, vinyl sulfones, vinylsulfonates, and vinylphosphonates. β-Substituted activated olefins do not normally react. Among electrophiles other than aldehydes, unactivated ketones undergo the Morita–Baylis–Hillman reaction only under high pressure, but activation such as in α-halo ketones, α-keto esters, α-keto lactones, and nonenolizable α-diketones often produces very reactive substrates. Imines also can be employed, provided they carry a sufficiently electronegative group on nitrogen.
This chapter covers catalyzed α-hydroxyalkylations and α-aminoalkylations of activated olefins. Transition metal catalyzed reactions of this type, are also included even though they proceed by a different mechanism. Transformations that require stoichiometric amounts of reagents or more than one step are summarized in the section on Comparison With Other Methods but are not included in the Tabular Survey. The Morita–Baylis–Hillman reaction has been reviewed before.
Keywords:
catalysts;
hydroxyalklyation;
aminoalkylation;
activated olefin;
acrylates;
allenic esters;
acrylamides;
acrylonitrile;
acrolein;
unsaturated ketones;
vinyl sulfoxides;
vinyl sulfones;
vinylsulfonates;
vinylphosphonates;
substituted activated olefins;
electrophile;
intramolecular reactions;
side reactions;
aldehydes;
diketones;
keto esters;
keto lactones;
imines;
iminium salts;
Aldol and Michael reactions;
Morita-Baylis-Hillman reaction;
comparison of methods;
synthetic utility;
experimental conditions;
experimental procedures;
tabular surveyread more
Citations
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Journal ArticleDOI
Recent Advances in the Baylis−Hillman Reaction and Applications
Journal ArticleDOI
aza-Baylis−Hillman Reaction
TL;DR: 1.5.1.
Journal ArticleDOI
Alternative energy input: mechanochemical, microwave and ultrasound-assisted organic synthesis
TL;DR: The purpose of this critical review is to highlight the advances in this general area by presenting such newer applications in organic synthesis by presenting microwave, ultrasound, sunlight, mechanochemical mixing and other alternative means of activation.
Journal ArticleDOI
The Enantioselective Morita–Baylis–Hillman Reaction and Its Aza Counterpart
TL;DR: This Minireview summarizes recent mechanistic insights and advances in the design and synthesis of small organic molecules for enantioselective MBH and aza-MBH reactions.
Journal ArticleDOI
Chalcogenides as organocatalysts.
Eoghan M. McGarrigle,Eddie L. Myers,Ona Illa,Michael Alan Shaw,Samantha L. Riches,Varinder K. Aggarwal +5 more
TL;DR: In this review, the many roles chalcogenides play as organocatalysts are described and the oxygen family, or the oxygenFamily, is described.
References
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Journal ArticleDOI
The use of microwave ovens for rapid organic synthesis
R. N. Gedye,Frank E. Smith,Kenneth Charles Westaway,Humera Ali,Lorraine Baldisera,Lena Laberge,John Rousell +6 more
TL;DR: In this paper, four different types of organic reactions have been studied and seven different organic compounds have been prepared, under pressure in a microwave oven, and considerable rate increases have been observed.
Journal ArticleDOI
Application of commercial microwave ovens to organic synthesis.
TL;DR: In this article, commercial microwave ovens have been safely used to dramatically reduce the reaction times (at comparable yield) of Diels-Alder, Claisen, and ene reactions.
Journal ArticleDOI
The baylis-hillman reaction : a novel carbon-carbon bond forming reaction
TL;DR: In this paper, an approach to chiral Baylis-hillman adducts is presented. But it does not address the problem of chiral activation and self-dimerization of alkenes.
Journal ArticleDOI
Synthetic potential of the tertiary-amine-catalysed reaction of activated vinyl carbanions with aldehydes
TL;DR: In this paper, the diaza-1,4bicyclo [2.2] octane, la quinuclidine and ses derives, the quinine
Journal ArticleDOI
Synthesis and Biological Activity of α‐Methylene‐γ‐butyrolactones
H. M. R. Hoffmann,Jürgen P. Rabe +1 more
TL;DR: In this paper, the synthesis of the heterocycle and classification of the synthetic methods are not only of practical interest, but also fundamentally important as a current example for the construction of an unusual 1,4-functionality distance and an α-substituted acrylic ester moiety which is susceptible to nucleophilic attack.