title: Generation of singlet oxygen from fragmentation of monoactivated 1,1-dihydroperoxides.
abstract: The first singlet excited state of molecular oxygen ((1)O(2)) is an important oxidant in chemistry, biology, and medicine. (1)O(2) is most often generated through photosensitized excitation of ground-state oxygen. (1)O(2) can also be generated chemically through the decomposition of hydrogen peroxide and other peroxides. However, most of these "dark oxygenations" require water-rich media associated with short (1)O(2) lifetimes, and there is a need for oxygenations able to be conducted in organic solvents. We now report that monoactivated derivatives of 1,1-dihydroperoxides undergo a previously unobserved fragmentation to generate high yields of singlet molecular oxygen ((1)O(2)). The fragmentations, which can be conducted in a variety of organic solvents, require a geminal relationship between a peroxyanion and a peroxide activated toward heterolytic cleavage. The reaction is general for a range of skeletal frameworks and activating groups and, via in situ activation, can be applied directly to 1,1-dihydroperoxides. Our investigation suggests the fragmentation involves rate-limiting formation of a peroxyanion that decomposes via a Grob-like process.
authors.affiliation: Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0304, USA.
authors.forename: Jiliang
authors.initials: J
authors.lastname: Hang
authors.forename: Prasanta
authors.initials: P
authors.lastname: Ghorai
authors.forename: Solaire A
authors.initials: SA
authors.lastname: Finkenstaedt-Quinn
authors.forename: Ilhan
authors.initials: I
authors.lastname: Findik
authors.forename: Emily
authors.initials: E
authors.lastname: Sliz
authors.forename: Keith T
authors.initials: KT
authors.lastname: Kuwata
authors.forename: Patrick H
authors.initials: PH
authors.lastname: Dussault
mesh_terms: D000080:Acetals / Q000737:chemistry; D002254:Carbonates / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007700:Kinetics; D008958:Models, Molecular; D008968:Molecular Conformation; D011522:Protons; D026082:Singlet Oxygen / Q000737:chemistry*; D013696:Temperature
chemical_list: D000080:Acetals; D002254:Carbonates; D011522:Protons; D026082:Singlet Oxygen; D006861:Hydrogen Peroxide; C034738:sodium percarbonate