Synthesis of N -aryl-hexaoxazadispiroalkanes using lanthanide catalysts

First Example of Catalytic Synthesis of Cyclic S-Containing Di- and Triperoxides

“…We assumed that cyclic thia-diperoxides may be synthesized by a reaction of pentaoxacanes with hydrogen sulfide in a similar manner to what we reported previously for the synthesis of cyclic aza-diperoxides via the reaction of pentaoxacanes with primary amines [46,47,50]. Preliminary experiments demonstrated that 7,8,10,12,13-pentaoxaspiro [5.7]tridecane [51] (1) reacts with H2S in the presence of the catalyst Sm(NO3)3·6H2O [46][47][48][49][50] for 6 h at room temperature in tetrahydrofuran (THF) solvent to produce 7,8,12,13-tetraoxa-10-thiaspiro [5.7]tridecane (8) in 98% yield. The reaction does not proceed in the absence of a catalyst (Scheme 1).…”

“…We developed a method for the preparation of thioperoxycarbocycles through the recyclization of pentaoxacanes and heptaoxadispiroalkanes with hydrogen sulfide under the action of lanthanide catalysts. We chose lanthanide catalysts due to their high activity in recyclization reactions involving primary amines, leading to cyclic N-containing diand triperoxides [46][47][48][49][50].…”

“…To expand the scope of applicability of the method for the synthesis of cyclic thio-peroxides developed here, we produced spiro-fused hexaoxathiocanes 18-20 by reaction of heptaoxacanes 15-17 [48] with hydrogen sulfide in THF (~20 • C, 6 h), catalyzed by Sm(NO 3 ) 3 ·6H 2 O (0.5 mol %). we observed that the size of the carbocycles in initial heptaoxadispiroalkanes 15-17 does not affect the yield of hexaoxathiocanes 18-20 (83-86%).…”

“…These signals reflect the process of cyclic interconversion in solution; therefore, we observed a set of signals with close chemical shifts for each of the individual compounds. The effect of the splitting of the NMR signals of the ring atoms is due to the presence of a multicomponent conformational equilibrium at room temperature, which can be assumed on the basis of published data on the identification of known heteroatom-containing peroxides, in particular azadi-and triperoxides [46][47][48][49][50]. The presence of one conformation was observed only in the case of 3-(adamantyl-2-yl)-1,2,4,5,7-tetraaoxatiocane (14), probably due to the rigidity of the structure of the spiroadamantane substituent.…”

“…The synthesis of the pentaoxacanes 1-7 was as reported in the literature [51]. The synthesis of the heptaoxadispiroalkanes 15-17 was also as reported in the literature [48]. THF was freshly distilled over LiAlH 4 .…”