Directed 1,3-dipolar cycloadditions of ylidene piperazine-2,5-diones

Chai, Christina L. L.; Edwards, Alison J.; Wilkes, Bronwyn A; Woodgate, Ruth C. J.

doi:10.1016/j.tet.2003.09.040

Cited by 12 publications

(8 citation statements)

References 17 publications

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“…Similar results were also obtained with nitrones [143] and nitrile oxides [144]. Cyclopentenyl glutamates were obtained by a [3 þ 2] cycloaddition of phosphorylides [145], obtained by nucleophilic attack of phosphines on allenic or alkynoic acid esters [146].…”

Section: Cycloadditionssupporting

confidence: 59%

Synthesis and Chemistry of α,β‐Didehydroamino Acids

Kazmaier¹

2009

Amino Acids, Peptides and Proteins in Organic Chemistry

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Section: Cycloadditionssupporting

confidence: 59%

Synthesis and Chemistry of α,β‐Didehydroamino Acids

Kazmaier¹

2009

Amino Acids, Peptides and Proteins in Organic Chemistry

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“…Donor substituents on BNOs, especially methoxyls, increased the reaction rate and yields of products of the both 4 and 5 . Because of a bulkiness of the BNO substituents, the regioselectivity of those reactions seems to be predetermined also by a volume and mutual interactions of three aromatic substituents close each to other in the position 3, 4, and 5 of the isoxazoline products …”

Section: Resultsmentioning

confidence: 99%

Prediction by ¹³C NMR of regioselectivity in 1,3‐dipolar cycloadditions of acridin‐9‐yl dipolarophiles

Vilková

Maľučká

Imrich

2015

Magnetic Reson in Chemistry

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Strong correlation was found between (13)C NMR chemical shifts of dipolarophilic CH=CH carbons and regioselectivity in 1,3-dipolar cycloadditions of new acridin-9-yl dipolarophiles with stable benzonitrile oxides (BNO). Accordingly, two starting dipolarophiles, (acridin-9-yl)-CH=CH-R (R = COOCH3 or Ph), reacted with three BNOs (2,4,6-trimethoxy, 2,4,6-trimethyl, and 2,6-dichloro) to give a mixture of two target isoxazoline regioisomers in which the acridine was bound either to isoxazoline C-4 carbon (4-Acr) or C-5 one (5-Acr). Methyl 3-(acridin-9-yl)propenoate afforded major 4-(acridin-9-yl)-isoxazoline-5-carboxylates (4-Acr) and minor 5-(acridin-9-yl)-4-carboxylates (5-Acr). 9-(2-Styryl)acridine regiospecifically afforded only 4-Acr cycloadducts. The ratios of regioisomers were compared with analogous reactions of acridin-4-yl dipolarophiles. Regioselectivity was dependent on a polarity of the CH=CH bond, donor effects in BNO, and stabilization by stacking of aromatic substituents in the products.

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“…80 Similarly, dhAAs can undergo [3+2] cycloadditions with azomethine ylides and other 1,3-dipoles, such as nitrones and nitrileoxides. 96,97,99,100 These reactions proceed smoothly at room temperature however, reaction conditions are often dictated by those necessary to generate the 1,3-dipole. Of note, the Raines group could achieve clean and quick 1,3 polar cycloadditions between dhAAs and electron-rich diazoacetamides in water/acetonitrile solvent systems.…”

Section: Cycloadditionsmentioning

confidence: 99%