108817-72-7

Upstream product

• 108817-71-6 2-methyl-5-methylene-3-phenyl-4-carbomethoxyisoxazolidine 
• 7166-18-9 methyl β-chlorocrotonate 
• 3376-23-6 N-methyl-α-phenylnitrone 
• 55370-56-4 3-Morpholinocrotonsaeure-methylester 
• 1233235-02-3 2,5-dimethyl-3-phenyl-2,3-dihydroisoxazole-4-carboxylic acid 
• 74-88-4 methyl iodide 
• 110601-13-3 2-Methyl-5-methylene-3-phenyl-isoxazolidine-4-carboxylic acid methyl ester 
• 18913-35-4 methyl buta-2,3-dienoate 
• 3376-23-6 C-phenyl-N-methylnitrone 

Downstream Products

• 20048-06-0 (E)-2-acetyl-1-phenyl-prop-1,2-enoic acid methyl ester 

Relevant academic research and scientific papers

Boronic acid catalysis for mild and selective [3+2] dipolar cycloadditions to unsaturated carboxylic acids

Herein, the concept of boronic acid catalysis (BAC) for the activation of unsaturated carboxylic acids is applied in several classic dipolar [3 + 2] cycloadditions involving azides, nitrile oxides, and nitrones as partners. These cycloadditions can be used to produce pharmaceutically interesting, small heterocyclic products, such as triazoles, isoxazoles, and isoxazolidines. These cycloadducts are formed directly and include a free carboxylic acid functionality that can be employed for fur-ther transformations, thereby avoiding prior masking or functionalization. In all cases, BAC provides faster reactions, under milder conditions, with much improved product yields and regioselectivities. In some instances, such as triazole formation from the reaction of azides with 2-alkynoic acids, catalysis with ort/io- nitrophenylboronic acid circumvents the undesirable product decarboxylation observed when using thermal activation. By using NMR spectroscopic studies, the boronic acid catalyst was shown to provide activation by a LUMO-lowering effect in the unsaturated carboxylic acid, likely via a monoacylated hemiboronic ester intermediate.

1,3-Dipolar Cycloaddition Reactions of Nitrones with Unsaturated Methylsulfones and Substituted Crotonic Esters

The cycloaddition reaction of nitrones to unsaturated methylsulfones and substituted crotonic esters gives a sole product or a mixture of tri- or tetra-substituted isoxazolidines, such that with disubstituted dipolarophiles the regiochemistry is dependent upon the nitrone and the vicinal electron-withdrawing group (CN or CO2Me) but with trisubstituted olefins, regiospeccific cycloadditions are observed.

Cycloaddition of Nitrones with Allenes. An Example of Steric Control of Regiochemistry

A study of the cycloaddition behavior of a series of electron-deficient allenes with C-phenyl-N-alkylnitrones has been carried out.The 1,3-dipolar cycloaddition proceeds in high yield with complete regiospecifity toproduce 5-methylene substituted isoxazol

A STUDY OF THE 5-EXO METHYLENE-ISOXAZOLIDINE TO 3-PYRROLIDINONE REARRANGEMENT

Dipolar cycloaddition of nitrones with carbomethoxy susbstituted allenes gives 5-exo methylene substituted isoxazolidines which rearrange upon thermolysis to 3-pyrrolidinones.