title: Photoisomerization as a trigger for Bergman cyclization: synthesis and reactivity of azoenediynes.
abstract: Cyclic enediynes 1a and 2a containing stable E-azo moiety (azoenediynes) have been synthesized. These compounds upon irradiation with long wavelength UV isomerize to the Z-compounds 1b and 2b, which can be thermally reisomerized to the Z compounds. Reactivity studies toward BC using DSC predictably indicate higher reactivity for the Z-isomers. Our studies may provide a novel way to modulate the reactivity of enediynes under thermal or photochemical conditions.
authors.affiliation: Department of Chemistry, Indian Institute of Technology, Kharagpur 721 302, India.
authors.forename: Moumita
authors.initials: M
authors.lastname: Kar
authors.forename: Amit
authors.initials: A
authors.lastname: Basak
authors.forename: Manish
authors.initials: M
authors.lastname: Bhattacharjee
mesh_terms: D000598:Amino Acids, Cyclic / Q000737:chemistry*; D001391:Azo Compounds / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D053281:Enediynes; D006863:Hydrogen-Ion Concentration; D007536:Isomerism; D047028:Macrocyclic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D010777:Photochemistry; D013053:Spectrophotometry
chemical_list: D000598:Amino Acids, Cyclic; D001391:Azo Compounds; D053281:Enediynes; D047028:Macrocyclic Compounds