Reactivity of 1,3-dipoles in aqueous solution. 2. Stereospecific reactions of benzonitrile oxides with oxygen, carbon, and nitrogen nucleophiles

1978 ◽  
Vol 43 (3) ◽  
pp. 388-393 ◽  
Author(s):  
Kieran J. Dignam ◽  
Anthony F. Hegarty ◽  
Paul L. Quain
Keyword(s):  
Aqueous Solution ◽  
Carbon And Nitrogen ◽  
Stereospecific Reactions ◽  
Nitrogen Nucleophiles

Detection of Semiquinone Radicals of N-Acylcatecholamines in Aqueous Solution

1985 ◽  
Vol 40 (7-8) ◽  
pp. 535-538 ◽  
Author(s):  
Martin G. Peter ◽  
Hartmut B. Stegmann ◽  
Hoang Dao-Ba ◽  
Klaus Scheffler
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Esr Spectra ◽  
Semiquinone Radicals ◽  
Spin Stabilization ◽  
Michael Type Addition ◽  
Nitrogen Nucleophiles

Abstract ESR-spectra were recorded during the oxidation of N-acetyldopamine and N-β-alanyldopamine in aqueous solutions. Semiquinone radicals were detected under conditions of spin stabilization by Zn2+ ions. The appearance of the spectra was the same in the presence or in the absence of proteins. No evidence was obtained for the formation of products that could have arisen eventually from intermolecular Michael-type addition of nitrogen nucleophiles.

Acyl cyanides as carbonyl heterodienophiles: application to the synthesis of naphthols, isoquinolones, and isocoumarins

1996 ◽  
Vol 74 (2) ◽  
pp. 221-226 ◽  
Author(s):  
Richard Connors ◽  
Elisabeth Tran ◽  
Tony Durst
Keyword(s):  
Key Words ◽  
Diels Alder ◽  
Acetonitrile Solution ◽  
Carbon And Nitrogen ◽  
Nitrogen Nucleophiles ◽  
Derivatives Of

Irradiation of 2-methylbenzoyl cyanide (3a) in acetonitrile solution results in the formation of its dimer, which upon loss of HCN gives rise to the cycloadduct 7a. The dimerization also proceeds efficiently with derivatives of 3a giving adducts 7b and 7c. When 2-methylaroyl cyanides are photolyzed in the presence of a more reactive acyl cyanide the mixed adducts 8a–e are obtained in excellent yields. The cycloadducts 7a–c and 8a–e react with carbon and nitrogen nucleophiles by a tandem addition–cyclization sequence furnishing substituted naphthols (10a and 10b) and isoquinolones (11a–d), respectively. Isocoumarins 12a and 12b were prepared from the adducts 8a and 8e by treatment with potassium tert-butoxide in THF. Key words: naphthols, isoquinolones, isocoumarins, synthesis of; acyl cyanides; hetero Diels–Alder.

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