Domino aza/oxa-hetero-Diels–Alder reaction for construction of novel spiro[pyrido[3′,2′:5,6]pyrano[2,3-d]pyrimidine-7,5′-pyrimidine]

2018 ◽  
Vol 5 (18) ◽  
pp. 2754-2758 ◽  
Author(s):  
Wen-Juan Yang ◽  
Qiu Sun ◽  
Jing Sun ◽  
Chao-Guo Yan
Keyword(s):  
Room Temperature ◽  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction ◽  
Methylene Dichloride

The unprecedented reaction of α,β-unsaturated N-arylaldimines with two molecular 5-arylidene-1,3-dimethylbarbituric acids in methylene dichloride at room temperature afforded unique spiro[pyrido[3′,2′:5,6]pyrano[2,3-d]pyrimidine-7,5′-pyrimidines] in moderate to good yields and with high diastereoselectivity.

scholarly journals Hetero-Diels–Alder reactions of hetaryl and aryl thioketones with acetylenic dienophiles

2015 ◽  
Vol 11 ◽  
pp. 576-582 ◽  
Author(s):  
Grzegorz Mlostoń ◽  
Paulina Grzelak ◽  
Maciej Mikina ◽  
Anthony Linden ◽  
Heinz Heimgartner
Keyword(s):  
High Pressure ◽  
Room Temperature ◽  
Thermal Conditions ◽  
Alder Reaction ◽  
Diels Alder ◽  
Hydrogen Shift ◽  
Diels Alder Reaction ◽  
Shift Sequence

Selected hetaryl and aryl thioketones react with acetylenecarboxylates under thermal conditions in the presence of LiClO4 or, alternatively, under high-pressure conditions (5 kbar) at room temperature yielding thiopyran derivatives. The hetero-Diels–Alder reaction occurs in a chemo- and regioselective manner. The initially formed [4 + 2] cycloadducts rearrange via a 1,3-hydrogen shift sequence to give the final products. The latter were smoothly oxidized by treatment with mCPBA to the corresponding sulfones.

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%.

scholarly journals Ionic liquid promoted Diels-Alder Reaction between anthrone and maleimides

2010 ◽  
Vol 8 (2) ◽  
pp. 356-360 ◽  
Author(s):  
Nitin Mirgane ◽  
Sandip Kotwal ◽  
Anil Karnik
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Room Temperature ◽  
Alder Reaction ◽  
Dual Role ◽  
Diels Alder ◽  
Environmentally Benign ◽  
Green Solvents ◽  
Imidazolium Ionic Liquid ◽  
Diels Alder Reaction

AbstractIonic liquids (IL) are gaining importance as green solvents. Imidazolium ionic liquid [bmim]+[Cl]−, an environmentally benign solvent, was found to promote the Diels-Alder reaction between anthrone and maleimides at room temperature with excellent yields. The ionic liquid played a dual role as solvent and catalyst.

Can a Diels–Alder reaction be accelerated in a supersaturated solvent at room temperature?

2016 ◽  
Vol 40 (10) ◽  
pp. 8355-8363 ◽  
Author(s):  
Amit S. Nagare ◽  
Arpan Manna ◽  
Anil Kumar
Keyword(s):  
Room Temperature ◽  
Alder Reaction ◽  
Diels Alder ◽  
Product Yields ◽  
Diels Alder Reaction

New carbohydrate-based supersaturated solvent for superior rates and high product yields.

scholarly journals Regiospecific synthesis of neuroprotective 1,4-benzoxazine derivatives through a tandem oxidation–Diels–Alder reaction

2015 ◽  
Vol 13 (12) ◽  
pp. 3749-3756 ◽  
Author(s):  
Khac Minh Huy Nguyen ◽  
Leslie Schwendimann ◽  
Pierre Gressens ◽  
Martine Largeron
Keyword(s):  
Room Temperature ◽  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction

Highly functionalized 1,4-benzoxazine derivatives have been synthesized at room temperature, with complete regiochemical control, through a tandem oxidation–Diels–Alder reaction.

Carbanion chemistry. A room temperature retro-Diels-Alder reaction

1976 ◽  
Vol 98 (25) ◽  
pp. 8273-8274 ◽  
Author(s):  
Elizabeth S. Bowman ◽  
Graham B. Hughes ◽  
John B. Grutzner
Keyword(s):  
Room Temperature ◽  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction
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