Distal -C-H functionalization of α-substituted cinnamates.

Development of a novel strategy for the palladium-catalyzed selective -C-H activation of α-substituted cinnamates and their heterocyclic analogues with various alkenes using nitrile as a directing group (DG) has been described. Importantly, we introduced naphthoquinone, benzoquinones, maleimides and sulfolene as coupling partners in the -C-H activation reaction for the first time. Notably, allylation, acetoxylation and cyanation were also achieved through distal -C-H functionalization.

Cascade annulation reaction (CAR): highly diastereoselective synthesis of pyranopyrazole scaffolds.

An unprecedented domino protocol for the novel synthesis of highly diverse and functionalized tetrahydro pyranopyrazole scaffolds using chalcone epoxide has been reported for the first time. This synthetic protocol generates three consecutive stereogenic centres in a highly diastereoselective manner with the formation of vicinal diol and a quaternary carbon centre. A wide range of substrates were utilized for the scope of this methodology and provided very good yields of pyranopyrazoles.

A distal vinyl shift (DVS) through quadruple domino reaction: synthesis of -vinyl benzoheterocyclic scaffolds.

A conceptually novel Distal Vinyl Shift (DVS) through quadruple domino reaction involving imine formation, oxazole/thiazole/oxazine formation, aza-Michael addition and selective retro oxa/aza-Michael addition leading towards -vinyl benzoxazoles/benzothiazoles/-vinyl 1,3-benzoxazines has been developed for the first time. This reaction is highly stereoselective and was carried out efficiently without using any catalyst as well as column chromatography purification with wide substrate scope in very good to excellent yields.