141248-84-2Relevant academic research and scientific papers
The SN2 Reactivity of 3,3-Disubstituted 1,2-Dioxetanes with Morpholine
Adam, Waldemar,Stoessel, Roland,Treiber, Alexander
, p. 2879 - 2884 (2007/10/02)
The reaction of morpholine with the 3-aryl-3-methyldioxetanes 1a-c (Y = 4-OMe, H, 4-NO2), the 3-(methoxymethyl)-3-phenyldioxetane (1d), and the 3-(halomethyl) 3-phenyldioxetanes 1e,f (X = Cl, Br) was investigated to determine the SN2 reactivity of these dioxetanes and the product distribution of the hydroxylamine ether 2 adducts and the dioxetane fragmentation products 3.It was shown that the overall reactivity and the product distribution are strongly dependent on the substituents of the dioxetanes 1.Thus, the reactivity of the dioxetanes 1 toward morpholine was demonstrated to correlate with the electron-accepting propensity of the substituents in the 3-position, while the product distribution depends on the electronic features of the primary dipolar adduct, which results from nucleophilic attack at the dioxetane peroxide bond.Electron-donating substituents (Y = 4-OMe) favor proton transfer from the hydroxylammonium site to the alkoxide ion due to the enhanced basicity of the latter, and, therefore, the formation of the hydroxylamine ether 2 is promoted.Additionally, electron-accepting substituents (Y = NO2) facilitate the Grob fragmentation of the primary dipolar adduct to the dioxetane cleavage products 3.The unexpected formation of the hydroperoxide 4f in the reaction of the dioxetane 1f with morpholine was shown to result from acid-catalyzed ring opening of the dioxetane by morpholinium bromide and subsequent morpholine trapping of the resulting stabilized, bromine-bridged benzylic cation.
Reaction of 1,2-dioxetanes with heteroatom nucleophiles: Adduct formation by nucleophilic attack at the peroxide bond
Adam, Waldemar,Heil, Markus
, p. 5591 - 5598 (2007/10/02)
The reactions of 3,3-disubstituted 1,2-dioxetanes 1 with numerous heteroatom nucleophiles, e.g., R2NH, R3N, RSH, R2S, CN-, SCN-, Br-, Cl-, OH-, and O2*-, were investigated. Initial nucleophilic substitution at the sterically less hindered site of the dioxetane peroxide bond leads to addition, deoxygenation, and fragmentation products. The observed SN2 chemistry was substantiated with the dioxetane le because bromide ion displacement by the proximate alkoxide ion site afforded epoxide products. Thus, with anionic nucleophiles the epoxy alcohol 8c was obtained in appreciable amounts, and triethylamine and DABCO gave with 1c exclusively the alkoxyammonium epoxides 4c and 5c. Moreover, the labile alkoxysulfonium epoxide 6c was detected as an intermediate in the deoxygenation of 1c by diphenyl sulfide. From the reaction of 1b-d with secondary amines were isolated the hydroxylamine derivatives 2 and 3, and the cyanide and thiocyanate ions gave with 1c,d five-membered-ring insertion products, namely, the carbonates 9c,d and the cyclic sulfite 10c.
