Introduction to Radical Triggered

A novel sulfonyl radical triggered selective iodosulfonylation and bicyclization of 1,6-dienes has been described for the first time.

The radical triggered cyclization and nitration of the aryl alkynoates proceeded in a cascaded manner via nitro radical addition to alkynoates, then 5-exo-trig spirocyclization and ester migration.

Herein, a radical triggered fragmentary cyclization cascade reaction of ene-ynamides is presented, providing a rapid access into [1,2]-annulated indoles by an intermolecular radical addition, intramolecular cyclization, desulfonylative aryl migration, and site-selective C(sp2)-N cyclization sequence.

The compounds' capacity to inhibit the peroxyl radical triggered formation of dichlorofluorescein (DCF) was investigated in a dose-dependent manner.

Moreover, as new reaction modes reported, advances have been made in the areas for arene C-C, C-N and C-O bond formation and radical triggered Smiles rearrangement has also enriched migrating units.

A selenium radical triggered switchable ortho/ipso-cyclization cascade of N-aryl alkynamides has been devised under metal-free conditions to access 3-selenyl quinolin-2-ones and 3-selenospiro[4,5]trienones in high yields (up to 98%).

Acyl radical triggered difunctionalizations of aryl olefins have been realized using oxime ester as the acyl precursor for the first time.

A simple and efficient Se-radical triggered cyclization/substitution cascade reaction of alkyne-tethered cyclohexadienones to afford 5-hydroxy-3-selenyl-4a,8a-dihydro-2H-chromen-6(5H)-ones has been developed.

An oxidative trifunctionalization of aryl alkynoates has been devised via the chalcogenide radical triggered intramolecular 1,4-aryl transfer/decarboxylation cascade to prepare 1,1-dichalcogenide tetrasubstituted alkenes in high yields (up to 98%).

The strategy involved radical triggered direct oxidative coupling of 5-aminopyrazoles with methyl ketones using aerial oxygen as a source of oxygen in newly generated carbonyl group.