Asymmetric Diels-Alder cycloaddition reactions with chiral .alpha.,.beta.-unsaturated N-acyloxazolidinones

1988 ◽  
Vol 110 (4) ◽  
pp. 1238-1256 ◽  
Author(s):  
David A. Evans ◽  
K. T. Chapman ◽  
J. Bisaha
Keyword(s):  
Diels Alder ◽  
Cycloaddition Reactions ◽  
Alpha Beta

A New Series of Organocatalysts for Diels-Alder Cycloaddition Reactions and Theoretical Analysis

2011 ◽  
Vol 15 (19) ◽  
pp. 3514-3522 ◽  
Author(s):  
Alessandro Casoni ◽  
Elena Borsini ◽  
Alessandro Contini ◽  
Alessandro Ruffoni ◽  
Sara Pellegrino ◽  
...  
Keyword(s):  
Theoretical Analysis ◽  
Diels Alder ◽  
Cycloaddition Reactions

1-[(E)-Butadienylsulfonyl]-3,3-dimethylbut-2-yl methacrylate

2006 ◽  
Vol 62 (4) ◽  
pp. o1369-o1370 ◽  
Author(s):  
Matthias Zeller ◽  
Allen D. Hunter ◽  
Paul Sampson ◽  
Nataliya Chumachenko
Keyword(s):  
Solid State ◽  
Title Compound ◽  
Diels Alder ◽  
Cycloaddition Reactions ◽  
Compound C

The title compound, C14H22O4S, was synthesized as a precursor for intramolecular Diels–Alder cycloaddition reactions. The (E)-buta-1,3-dienyl and methacrylate ester systems adopt an s–trans conformation in the solid state, with the two π units in both cases being almost coplanar.

scholarly journals Enhancing the reactivity of 1,2-diphospholes in cycloaddition reactions

2015 ◽  
Vol 11 ◽  
pp. 169-173 ◽  
Author(s):  
Almaz Zagidullin ◽  
Vasili Miluykov ◽  
Elena Oshchepkova ◽  
Artem Tufatullin ◽  
Olga Kataeva ◽  
...  
Keyword(s):  
Room Temperature ◽  
Cycloaddition Reaction ◽  
Alder Reaction ◽  
Diels Alder ◽  
Alkyl Halides ◽  
Ethyl Iodide ◽  
Para Position ◽  
Cycloaddition Reactions ◽  
Diels Alder Reaction ◽  
Heating Up

Two different approaches have been employed to enhance the reactivity of 1-alkyl-1,2-diphospholes – the introduction of electron-withdrawing groups either at the phosphorus atoms or in the para-position of the arene ring. The alkylation of sodium 1,2-diphospha-3,4,5-triphenylcyclopentadienide with alkyl halides Hal-CH2-R (R = CN, COOEt, OMe, CH2OEt) results in corresponding 1-alkyl-3,4,5-triphenyl-1,2-diphospholes (alkyl = CH2CN (1a), CH2COOEt (1b), CH2OMe (1c), and (CH2)2OEt (1d)), which spontaneously undergo the intermolecular [4 + 2] cycloaddition reactions at room temperature to form the mixture of the cycloadducts, 2a–c, respectively. However the alkylation of sodium 1,2-diphospha-3,4,5-tri(p-fluorophenyl)cyclopentadienide with ethyl iodide leads to stable 1-ethyl-3,4,5-tris(p-fluorophenyl)-1,2-diphosphole (1e), which forms the [4 + 2] cycloadduct 2,3,4,4a,5,6-hexa(p-fluorophenyl)-1-ethyl-1,7,7a-triphospha-4,7-(ethylphosphinidene)indene (2e) only upon heating up to 60 °C. With further heating to 120 °C with N-phenylmaleimide, the cycloadducts 2a–c and 2e undergo the retro-Diels–Alder reaction and form only one product of the [4 + 2] cycloaddition reaction 3a–с, 3e with good yields up to 65%.

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