121034-00-2Relevant academic research and scientific papers
High 1,2-Asymmetric Induction in Radical Reactions: Radical Addition to γ-Hydroxy α,β-Unsaturated Carboxylic Esters and Sulfones
Ogura, Katsuyuki,Kayano, Akio,Akazome, Motohiro
, p. 3091 - 3101 (2007/10/03)
High 1,2-asymmetric induction was realized by the addition of a 1-hydroxy-1 -methylethyl radical to conformationally flexible (E)-γ-hydroxy α,β-unsaturated carboxylic esters and sulfones (1 and 2, respectively). Upon the irradiation (> 290 nm) of (E)-1 and benzophenone in 2-propanol, the 1-hydroxy-1-methylethyl radical was generated in situ and added to (E)-1 with high anti-stereoselectivity. The bulkier is the γ-alkyl group of (E)-1, the higher does the selectivity become. Similarly, a radical addition to the acetates of (E)-1 and (E)-2 proceeded stereoselectively in an anti fashion, whereas (Z)-2 exhibited syn-stereoselectivity. The mechanism for these stereoselective radical additions is discussed.
"Syn-Effect" in the Conversion of (E)-Vinylic Sulfones to the Corresponding Allylic Sulfones
Hirata, Takaki,Sasada, Yoshihiro,Ohtani, Takashi,Asada, Takahiro,Kinoshita, Hideki,et al.
, p. 75 - 96 (2007/10/02)
It was found that (E)-vinylic sulfones preferentially afford (Z)-allylic sulfones as kinetically-controlled products by treatment with a base under mild conditions, while (Z)-vinylic sulfones give (E)-allylic sulfones.Such stereochemical relationship was
A SIMPLE METHOD FOR THE SYNTHESIS OF γ-FUNCTIONALIZED VINYL AND ALLYL SULFONES
Najera, Carmen,Perez-Pinar, Alfonso,Sansano, Jose M.
, p. 6337 - 6352 (2007/10/02)
The synthesis of γ-functionalized vinyl sulfones 3 have been carried out directly starting from dibromides 2 derived from allyl sulfones 1 by reaction with different nucleophiles.The process is stereoselective affording compounds 3 with E configuration ex
Stereochemistry of the Conversion of γ-substituted (E)-Vinylsulfones to the Corresponding Allylsulfones. Determination of the Relative Degree of "Syn-Effect"
Inomata, Katsuhiko,Hirata, Takaki,Suhara, Hiroshi,Kinoshita, Hideki,Kotake, Hiroshi,Senda, Hitoshi
, p. 2009 - 2012 (2007/10/02)
The relative degree of "syn-effect" for the γ-substituted vinylsulfones in their conversion to the corresponding allylsulfones with 1,8-diazabicycloundec-7-ene (DBU) was determined by observing E/Z ratios of the resulting allylsulfones as follows:
Palladium(II)-Catalyzed Acetoxylation and Chlorination of 2-Alkenyl p-Tolyl Sulfones
Ogura, Katsuyuki,Shibuya, Nobuhiro,Takahashi, Kazumasa,Iida, Hirotada
, p. 1092 - 1096 (2007/10/02)
2-Alkenyl p-tolyl sulfones were converted into the corresponding 3-acetoxy (or chloro)-1-alkenyl p-tolyl sulfones via ?-allylpalladium complexes which reacted regiospecifically with a nucleophile such as acetate anion or chloride anion in the presence of
PALLADIUM(II)-ASSISTED CONVERSION OF A 2-ALKENYL SULFONE INTO A 3-ACETOXY(OR CHLORO)-1-ALKENYL SULFONE
Ogura, Katsuyuki,Shibuya, Nobuhiro,Iida, Hirotada
, p. 1519 - 1522 (2007/10/02)
2-alkenyl p-tolyl sulfone was converted into the corresponding 3-acetoxy-1-alkenyl p-tolyl sulfone via a ?-allyl palladium complex which underwent regiospecific attack of a nucleophile, acetate ion, and the reaction conditions for predominant formation of
