Methods of Cleavage of 2-Isoxazolines

Regio- and diastereoselective access to densely functionalized ketonesviathe Boekelheide rearrangement of isoxazolineN-oxides

“…1 Despite great progress in developing new methods for aldol reactions, 1 e – k the regio- and diastereoselective synthesis of aldols A is still challenging in many cases (Scheme 1). An alternative to the classical aldol condensation is the so-called “isoxazoline route”, 2 which consists of hydrogenolysis of isoxazolines B generated by a [3 + 2] cycloaddition of nitrile oxides C with alkenes D (Scheme 1). This strategy received much attention in the end of the 20th century and was successfully exploited in the total synthesis of numerous natural products.…”

Copper-Catalyzed Annulation Reaction of Alkenes and N-Alkyl(aryl)-1-(methylthio)-2-nitroethenamine: an Approach for the Synthesis of Isoxazole Derivatives

“…Isoxazolines and their derivatives 4,5-dihydroisoxazoles are very important five-membered nitrogen- and oxygen-containing pentaheterocycles, which are often found in drugs, natural products, and bioactive molecules − with significant biological activities, such as antiviral, antifungal, anticancer, and antitumor properties. They are also the precursors for the synthesis of many important compounds, including 1,3-bifunctional compounds, β-amino alcohols, γ-amino alcohols, β-hydroxy ketones, β-hydroxyoximes, β-hydroxy nitriles, and α,β-unsaturated carbonyl compounds, along with a wide variety of complex natural products. − Furthermore, these heterocycles are the important structural motifs in medicinal chemistry and also employed as important chiral ligands in organic synthesis …”

N–O Cleavage reactions of heterobicycloalkene-fused 2-isoxazolines

“…2-Isoxazolines 1 are practical precursors to countless structural motifs found in nature. Various carbonyl compounds 2 , β-hydroxyimines 3 , β-hydroxynitriles 4 , β-aminoketones 5 , γ-aminoalcohols 6 and oximes 7 can all be readily attained through ring cleavage of 2-isoxazolines using suitable reagents for each transformation ( Scheme 1 ) [ 1 – 7 ]. In recent years, there has been considerable interest in applying this isoxazoline-cleavage methodology to the preparation of biologically active natural products, including novel antibacterial, antifungal and anticancer treatments [ 8 – 11 ].…”