Active sulfuration of norbornenes

exo-9,10,11-Trithiatetracyclo[5.5.1.02,6.08,12]tridec-3-ene

“…The mechanism of this reaction has not been established and conflicting theories have been proposed (Pryor, 1962); however, free-radical mechanisms are favored (Davies, 1970). The trithiolanes of 8,9,10-trinorbornene (Shields & Kurtz, 1969) and of endo-dicyclopentadiene, exodicyclopentadiene and tricyclopentadiene (Emsley, Griffiths & Jayne, 1979) were prepared in high yields by heating the olefins and elemental sulfur in DMF. A similar result was obtained upon the irradiation of a solution of 8,9,10-trinorbornene and sulfur (Inoue, Tezuka & Oae, 1978).…”

Synthesis, structure, and ring inversion of a trithiolane (6b,12b-epitrithioacenaphtho[1,2-a]acenaphthylene)

“…In general, trithiolanes are thermodynamically more stable than the corresponding pentathiepanes, which occasionally decompose to trithiolanes and SCHEME 1 SCHEME 2 sulfur when dissolved in polar solvents or on attempted purification by silica-gel column chromatography [7] or distillation [9]. In contrast to these results, the pentathiepane 2 was produced as the sole product for the sulfuration of acenaphtho[1,2a]acenaphthylene 1 with elemental sulfur in dimethylformamide (DMF) at 135ЊC [18,19].…”

“…Thus, 1,2,3-trithioles [1][2][3] and 1,2,3,4,5-pentathiepins [3,4], unsaturated five-membered trisulfides and seven-mem-bered pentasulfides, respectively, were investigated briskly in syntheses, reactions, and structures, since naturally occurring benzotrithioles and benzopentathiepins were isolated [5]. 1,2,3-Trithiolanes [1,2] and 1,2,3,4,5-pentathiepanes [4,[6][7][8][9], which are saturated analogs of trithioles and pentathiepins, respectively, were also studied mainly on preparations and reactions. A few reports dealt with the crystal structure of 1,2,3-trithiolanes [10-12] and 1,2,3,4,5pentathiepanes [13].…”

Novel Thiofomylation of Primary and Secondary Amines Using N-Aryl-1,2,3,4,5,7-Pentathiazocanes

“…All these results suggested in situ generation of some reactive sulfur species, such as triatomic sulfur (S 3 ), diatomic sulfur (S 2 ), and so on, through thermally or amine-induced ring fission of N-aryl-1,2,3,4,5-pentathiazocanes 1. [31][32][33][34][35][36][37][38][39][40][41] However, the yield of 8 obtained through thermal reaction of 1a and norbornene in the absence of an amine was relatively lower than the case of the similar trapping experiment in the presence of diethylamine. Greer and Brzostowska already reported a novel generation of triatomic sulfur (S 3 ) through a similar ring fission of varacin by nucleophilic attack of the internal primary amino group toward a sulfur atom of the 1,2,3,4,5-pentathiepin ring, 35,36 and these results suggested that ring fission of 1 was initiated by added amines.…”