Approach to regiochemistry using local softness in 1, 3-dipolar cycloadditions

Highly diastereoselective 1,3-dipolar cycloadditions of chiral non-racemic nitrones to 1,2-diaza-1,3-dienes: an experimental and computational investigation.

Asymmetric 1,3-dipolar cycloadditions between 1,2-diaza-1,3-dienes and chiral non-racemic nitrones to give 3-substituted-5-diazenyl isoxazolidines were studied both experimentally and theoretically. Whereas cyclic nitrones provide complete selectivity for the cycloaddition reaction (only one isomer is obtained), acyclic nitrones derived from D-glyceraldehyde and D-galactose lead to 1 : 1 mixtur...

Use of Local Softness for the Interpretation of Reaction Mechanisms

The application of reactivity parameters derived from density functional theory in a local sense, in particular the softness and Fukui function, to interpret and predict the mechanisms of various organic reactions has been discussed. Local softness is shown to be successful in determining the site-selectivity and regiochemistry and can be used as an alternative to the traditional frontier orbit...

1,3-Dipolar Cycloadditions of Diazo Compounds in the Presence of Azides.

The diazo group has untapped utility in chemical biology. The tolerance of stabilized diazo groups to cellular metabolism is comparable to that of azido groups. However, chemoselectivity has been elusive, as both groups undergo 1,3-dipolar cycloadditions with strained alkynes. Removing strain and tuning dipolarophile electronics yields diazo group selective 1,3-dipolar cycloadditions that can b...

Nitrones as dipoles for rapid strain-promoted 1,3-dipolar cycloadditions with cyclooctynes.

Strain-promoted cycloadditions of nitrones with cyclooctynes (k(2) = 1.5 M(-1) s(-1) at 25 degrees C) are up to 25 times more rapid than comparable reactions of azides.

Theoretical study of 1, 3-dipolar cycloadditions of nitrone and fulminic acid with substituted ethylenes