4247-57-8Relevant academic research and scientific papers
Trapping Reactions of Sulfenes Generated from Sulfonic Acid Derivatives and Bases, 2. Cycloadditions of 1,2,3,4,5-Pentamethylcyclopentadiene and 1,3-Diphenylbenzofuran with Sulfenes
Opitz, Guenter,Deissler, Michael,Rieth, Karlheinz,Wegner, Ralf,Irngartinger, Hermann,Nuber, Bernhard
, p. 2151 - 2164 (2007/10/03)
Sulfenes 2a-o, generated in situ from sulfonyl chlorides and Et3N, are trapped by 1,2,3,4,5-pentamethylcyclopentadiene (6) to give cycloadducts 8a-o containing the 7-methyl group in anti position.With mesylsulfene (7), formed in situ from mesyl chloride/Et3N in MeCN solution, the cycloaddition to endo/exo-9 (X-ray analyses) is accompanied by a (2 + 2> cycloaddition to 10 (X-ray analysis). (+)-10-Camphorsulfonyl chloride/Et3N afforded only two (and no more) diastereomeric cycloadducts (endo/exo-8d).Et3N can be replaced by Me3N, N,N,N',N'-tetramethylnaphthalene-1,8-diamine or NaH, the sulfonyl chlorides to a limited extent by sulfonyl fluorides, sulfonic acid anhydrides or aryl esters.Formation of 8p from 6 and dichloromethanesulfonyl chloride requires NaH or AgNO3 or tertiary amine/AgNO3.N-(2-Methyl-1-propenyl)pyrrolidine is more reactive than 6 in trapping sulfene 2a. 6, however, is more efficient sulfene scavenger than 1,3-diphenylbenzofuran (19), which reacts with sulfene 2d by cycloaddition and SO2 extrusion to give ketone 21d in only 18percent yield. - Keywords: 1,2,3,4,5-Pentamethylcyclopentadiene; 1,3-Diphenylbenzofuran; Sulfenes; Cycloaddition
Secondary Reactions of Sulfenes from Sulfonyl Chlorides and Tertiary Amines, 1. - On the Competing Formation of Sulfene-Trialkylamine S,N- and C,N-Adducts
Opitz, Guenter,Rieth, Karlheinz,Ehlis, Thomas
, p. 1563 - 1569 (2007/10/02)
Phenylmethanesulfonyl chloride (1 a) reacts with an excess oif triethylamine in acetonitrile solution at -40 deg C to give stilbene episulfone (9 a, 95percent) via the phenylsulfene-triethylamine S,N-adduct 5 ah.With trimethylamine and quinuclidine the yield of stilbene is reduced by the additional formation of (benzylsulfonyl)phenylsulfene-amine S,N-adducts 11 ag and 11 ae and C,N-adducts 15 ag and 15 ae which was proven by reaction with dimethylamine to 16 and by hydrolysis to 17-19, respectively. 1 d reacts with triethylamine yielding 94percent of α-chloro sulfones 4 d and 6 d via pentamethylenesulfene-triethylamine S,N-adduct 5 dh, with trimethylamine, however, C,N-adduct 12 dg is obtained which is easily oxidized to 20 dg (47percent).The air-sensitive dimethylsulfene-trimethylamine C,N-adduct 12 cg was isolated and characterized.
