TMSOTf mediated reaction of alkynyl vinylogous carbonates serendipitously gave 1,4-oxazepine and dihydropyran dienes via transposition of ethyl acrylate moiety involving intramolecular cascade Prins type cyclization/retro-oxa-Michael reaction/cycloisomerisation. The developed atom-economical protocol...

Regioselective amination of polyhalogenated heteroarenes (especially pyrimidines) has extensive synthetic and commercial relevance for drug synthesis applications but is plagued by the lack of effective synthetic strategies. Herein, we report the Cu(II)/PTABS-promoted highly regioselective nucleophilic aromatic substitution (S N Ar) of polychlorinated pyrimidines assisted by DFT predictions of the bond dissociation energies of different C−Cl bonds. The unique reactivity of Cu(II)-PTABS has been attributed to the coordination/activation mechanism that has been known to operate in these reactions, but further insights into the catalytic species have also been provided.

Stereoselective syntheses of pyrrolidines and piperidines bearing hydrophobic chains have been achieved through a metal free, Lewis acid-mediated 5/6-endo-dig reductive hydroamination cascade of enynyl amines. The brevity of the developed strategy allowed for the collective stereoselective total synthesis of various alkaloids, including (±)-pyrrolidine cis-225H, (±)-epi-197B, (±)-epi-225C, the family of (+)-solenopsins and (+)-isosolenopsins, and the formal synthesis of (±)-bgugaine and (+)-azimic acid.Letter pubs.acs.org/OrgLett