Diels-Alder Reaction Compilation

Diels-Alder Reaction Dienophiles Difluoroallene Dioxoindoles Dioxolanyliums Discovery of Diels-Alder reaction Discovery of orbital symmetry conservation rule Diterpenes Domino Drtmane sesquiterpenes Compilation 0031, 9804, 9742, 9741. 9737, 9705, 9410, 9406, 9306, 9218, 9118 9126 9705 9833, 9604 9222 9222 0003 0033, 0024, 9835, 9014 9116... 

Annual Volume 71 contains 30 checked and edited experimental procedures that illustrate important new synthetic methods or describe the preparation of particularly useful chemicals. This compilation begins with procedures exemplifying three important methods for preparing enantiomerically pure substances by asymmetric catalysis. The preparation of (R)-(-)-METHYL 3-HYDROXYBUTANOATE details the convenient preparation of a BINAP-ruthenium catalyst that is broadly useful for the asymmetric reduction of p-ketoesters. Catalysis of the carbonyl ene reaction by a chiral Lewis acid, in this case a binapthol-derived titanium catalyst, is illustrated in the preparation of METHYL (2R)-2-HYDROXY-4-PHENYL-4-PENTENOATE. The enantiomerically pure diamines, (1 R,2R)-(+)- AND (1S,2S)-(-)-1,2-DIPHENYL-1,2-ETHYLENEDIAMINE, are useful for a variety of asymmetric transformations hydrogenations, Michael additions, osmylations, epoxidations, allylations, aldol condensations and Diels-Alder reactions. Promotion of the Diels-Alder reaction with a diaminoalane derived from the (S,S)-diamine is demonstrated in the synthesis of (1S,endo)-3-(BICYCLO[2.2.1]HEPT-5-EN-2-YLCARBONYL)-2-OXAZOLIDINONE. 

Diels-Alder reactions with acyclic and carbocyclic dienes are compiled in Scheme 5. The comparison between the Lewis-acid catalyzed and pressure-induced reaction (entry 1) shows that the application of high pressure, particularly in acid-sensitive systems, can sometimes lead to a better yield. Furthermore, pressure may shift the product ratio, if the activation volumes of the competing reactions are different, so that the application of pressure may also be useful in highly reactive systems, e.g. the reactive indenone 17 as dienophile, provided that a shift in the product ratio is desired. At atmospheric... 

Mur 207), has received renewed interest in recent years. A fine review covering the intermolecular asymmetric Diels-Alder reaction was compiled by Mori 208>. In this article the use of terpenes and carbohydrates as chiral auxiliaries is discussed no amino acid derivatives are mentioned in this context. A chiral a-hydroxycarboxylic acid derivative was also used to achieve an asymmetric Diels-Alder reaction 209). High asymmetric induction could be detected in the intramolecular Diels-Alder reaction of chiral molecules. 

As noted above, a recent compilation of values of AV 79 indicates that the vast majority of values fall within a range 30 cm3/mol. These correspond approximately at 100 MPa relative to ambient pressure, to a rate acceleration or retardation of a factor of about 3.5. Some reactions within organic chemistry, for example, Diels-Alder reactions, exhibit volumes of activation approaching —50cm3/mol. Volumes of... 

For the less polar but similar Diels-Alder reaction, the dimerization of cyclopentadiene, which has also been studied in the gas phase, the data compiled in Table XV.3 show that over a very large range of solvents there are small changes in A and E and very little change in... 

Since the disclosures that the thermal dimerizations of acrolein and methyl vinyl ketone provide the 3,4-dihydro-2//-pyrans (1, 2) derived from 4ir and 2Tt participation of the a,3-unsaturated carbonyl compound in a Diels-Alder reaction, an extensive series of related observations have been detailed. This work has been the subject of several comprehensive reviews - - including the Desimoni and Tacco-ni extensive tabular compilation of work through 1974. Consequently, the prior reviews should be consulted for thorough treatments of the mechanism, scope, and applications of the [4 + 2] cycloaddition reactions of a,3-unsaturated carbonyl compounds. The [4 + 2] cycloaddition reactions of 1-oxa-1,3-butadienes with their 4-it participation in the Diels-Alder reaction exhibit predictable regioselectivity with the preferential or exclusive formation of 2-substituted 3,4-dihydro-2W-pyrans (equation 1). The exceptions to the predicted regioselectivity that have been observed involve the poorly matched [4 + 2] cycloaddition reaction of an electron-deficient l-oxa-l,3-butadiene with an electron-deficient dienophile, e.g. methyl crotonate or methacrolein. - Rigorous or simplified theoretical treatments of the [4 + 2] cycloaddition reaction of 1-oxa-1,3-butadienes predict the preferential formation of 2-substituted 3,4-dihy-dro-2f/-pyrans and accommodate the preferred endo approach of the reactants in which the carbon-carbon bond formation is more advanced than carbon-oxygen bond formation, i.e. a concerted but nonsynchronous [4 + 2] cycloaddition reaction. ... 

For a large compilation of Diels-Alder reactions, see A. S. Onishchenko, Diene Synthesis, Israel Program for Scientific Translations, Jerusalem, 1964 Dienovyi Sintez, Izdatel stvo Akademii Nauk, Moskva, 1963. 

It is the entropic assistance provided by the intramolecular reaction that provides the driving force necessary to overcome the reluctant participation of the 2-azadiene in a Diels-Alder reaction. Prior reviews12 should be consulted for compiled, tabulated examples. 

Since the thermal dimerizations of acrolein and methyl vinyl ketone were shown to provide the 3,4-dihydro-2//-pyrans l,12 an extensive range of related observations have been disclosed. This work has been the subject of several reviews.3 14 Only the work reported since the extensive Desimoni and Tacconi account5 of the Diels-Alder reaction of a,/3-unsatu-rated carbonyl compounds, 1-oxabutadienes bearing an oxygen atom at the diene terminus, has been detailed herein. The prior reviews should be consulted for an excellent discussion of the mechanism, scope, and application of the [4 + 2] cycloaddition reactions of a,/3-unsaturated carbonyl compounds as well as for extensive tabular compilations of the work through 1974.3-6... 

Extensive reviews have summarized - and compiled the results of many of the studies to date, and Table 10-XI summarizes representative inter- and intramolecular Diels-Alder reactions of 1,2,4,5-tetrazines with carbon dienophiles. Extensive investigations of the participation of electron-deficient 1,2,4,5-tetrazines in inverse electron demand Diels-Alder reactions with electron-rich heterodienophiles have been described, and much of this work is summarized in TaUe 10-XU. 

In asymmetric Diels-Alder reactions of chiral electron-poor alkenes the dienes compiled in the schemes given below have been used as indicated in the tables on the following pages. 

Non-catalyzed Diels-Alder reactions of chiral dienes with the achiral dienophiles compiled below have been widely studied. As dienophiles especially quinones (1), maleic anhydride (2), nitro-substituted alkenes (5) and acrylates (4) have been examined. 

The purpose of tWs chapter is to examine the scope of the intramolecular Diels-Alder reaction, with particular emphasis on methods for assembling the starting triene. While an exhaustive compilation has not been intended, the attempt has been made to include examples of every sort of diene and dienophile, including those with heteroatom substitution. 

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