ChemInform Abstract: 1,3-Dipolar Cycloaddition Reactions of Isothiazol-3(2H)-ones with Nitrile Oxides. An Unexpected Site Selectivity of the Carbonyl Bond of 5-Benzoyl-isothiazol-3(2H)-one.

ChemInform ◽  
2010 ◽  
Vol 27 (50) ◽  
pp. no-no
Author(s):  
E. COUTOULI-ARGYROPOULOU ◽  
C. ANASTASOPOULOS
Keyword(s):  
Dipolar Cycloaddition ◽  
Cycloaddition Reactions ◽  
Nitrile Oxides ◽  
Site Selectivity ◽  
Carbonyl Bond

Spiroheterocycles via Regioselective Cycloaddition Reactions of Nitrile Oxides with 5-Methylene-1H-pyrrol-2(5H)-ones

2010 ◽  
Vol 63 (3) ◽  
pp. 445 ◽  
Author(s):  
Nicola J. Beattie ◽  
Craig L. Francis ◽  
Andris J. Liepa ◽  
G. Paul Savage
Keyword(s):  
Cycloaddition Reaction ◽  
Biphasic System ◽  
Dipolar Cycloaddition ◽  
Cycloaddition Reactions ◽  
Nitrile Oxides ◽  
Facial Selectivity

Substituted 5-methylene-1H-pyrrol-2(5H)-ones underwent a 1,3-dipolar cycloaddition reaction with nitrile oxides to give the corresponding spiro heterocycles. Critical to this reaction was the development of a biphasic system for base-induced dehydrohalogenation of hydroximoyl chlorides, to give nitrile oxides, in the presence of a base-sensitive dipolarophile. A substituted N-tolyl 5-methylene-1H-pyrrol-2(5H)-one exhibited atropisomerism, which in turn led to a 4:1 facial selectivity during cycloaddition.

1,3-Dipolar Cycloadditions of a Chiral Oxazolidinone With Nitrones and Nitrile Oxides

1995 ◽  
Vol 48 (9) ◽  
pp. 1511 ◽  
Author(s):  
SG Pyne ◽  
J Safaei-G ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Hydrogen Atmosphere ◽  
Dipolar Cycloaddition ◽  
Cycloaddition Reactions ◽  
The Novel ◽  
X Ray ◽  
Dipolar Cycloadditions ◽  
Nitrile Oxides ◽  
Exocyclic Methylene

The 1,3-dipolar cycloaddition reactions of the chiral oxazolidinone (1) and nitrones are highly regioselective and only 5,5-disubstituted isoxazolidine adducts are formed. These reactions occur under equilibrating conditions to give the more stable adducts that result from addition to the exocyclic methylene of (1) from the sterically more hindered π-face. The endo adducts are generally thermodynamically favoured. In one case the novel azetidine (21) was formed from the treatment of the adduct (4a) with palladium hydroxide on carbon under a hydrogen atmosphere. The major adducts from the reaction of (1) and nitrile oxides (16a,b) had the expected stereochemistry, addition of the 1,3-dipole having occurred from the less hindered π-face of the exocyclic methylene of (1). The stereochemistry of many of these products has been elucidated by single-crystal X-ray structural determinations.

1,3-dipolar cycloaddition reactions of nitrile oxides to prop-1-ene-1,3-sultone

2003 ◽  
Vol 40 (6) ◽  
pp. 1071-1074 ◽  
Author(s):  
Li Tian ◽  
Guo-Yan Xu ◽  
Yong Ye ◽  
Lun-Zu Liu
Keyword(s):  
Dipolar Cycloaddition ◽  
Cycloaddition Reactions ◽  
Nitrile Oxides

1,3-Dipolar cycloadditions of nitrile oxides with 7-oxa- and 7-azabenzonorbornadienes

2014 ◽  
Vol 92 (7) ◽  
pp. 635-639 ◽  
Author(s):  
Jaipal R. Nagireddy ◽  
Emily Carlson ◽  
William Tam
Keyword(s):  
Dipolar Cycloaddition ◽  
Cycloaddition Reactions ◽  
Biological Testing ◽  
Dipolar Cycloadditions ◽  
Nitrile Oxides ◽  
Anti Cancer ◽  
Efficient Construction ◽  
Cancer Activity

Dipolar cycloaddition reactions allow for the efficient construction of five-membered heterocycles, often with diverse medicinal applications. We examined the 1,3-dipolar cycloaddition of 7-oxabenzonorbornadienes and 7-azabenzonorbornadienes with acetonitrile oxide and benzonitrile oxide, achieving an assortment of heterobicycle-fused isoxazolines with good to excellent yields. All isoxazolines were consistently directed to the exo face of the bicyclic framework with complete stereoselectivity. Preliminary biological testing of the adducts also showed positive anti-cancer activity, suggesting their potential pharmaceutical utility.

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