69063-45-2Relevant academic research and scientific papers
Synthesis and Applications of 3-Phenylthio-2-sulfolenes
Chou, Shang-Shing P.,Chao, Mao-Hsun
, p. 53 - 59 (1996)
Treatment of 3-phenylthio-2-sulfolene (1) with an equimolar proportion of butyllithium at -78 °C in THF followed by addition of an electrophile gave the 2-substituted 3-phenylthio-2-sulfolenes (2). The deprotonation was found to proceed only at the vinylic C-2 position. Some of the 2-sulfolenes 2 underwent desulfonylation upon heating with base. Of particular interest was the conversion of 3-phenylthio-2-trimethylsilyl-2-sulfolene (2h) to its 3-sulfolene isomer 6 by sequential addition of butyllithium and salicylic acid at low temperatures. The 3-sulfolene 6 was desulfonylated by Kugelrohr distillation at 150 °C under vacuum to give (Z)-2-phenylthio-1-trimethylsilyl-1,3-butadiene (8). The regiochemistry of the Diels Alder reaction of this highly reactive diene 8 was found to be controlled by the phenylthio group, and the stereochemistry is endo addition. Diene 8 was oxidized to its sulfone derivative 12 which also underwent a stereospecific Diels-Alder reaction.
Synthesis and applications of tetrahydro-2-pyridinones via aza-Diels - Alder reactions of thio-substituted 1,3-dienes with arylsulfonyl isocyanates
Chou,Hung
, p. 2450 - 2462 (2007/10/03)
The first aza-Diels - Alder reactions of arylsulfonyl isocyanates with thio-substituted 1,3-dienes via the 3-sulfolene precursors 1 gave the cyclized products 3 with complete control of chemo- and regioselectivity. The cyclized products 3a and 5 underwent further reactions with nucleophiles and bases to give useful heterocyclic compounds. The N-tosyl group of the cyclic products could be selectively replaced by hydrogen or another substituent.
