259532-53-1Relevant academic research and scientific papers
New approaches to enantioselective fluorination: Cinchona alkaloids combinations and chiral ligands/metal complexes
Shibata, Norio,Ishimaru, Takehisa,Nakamura, Shuichi,Toru, Takeshi
, p. 469 - 483 (2008/01/03)
The selective construction of carbon-fluorine bonds is of great interest to medicinal chemists because the replacement of a hydrogen or an oxygen atom with a fluorine atom in biologically active molecules can confer the molecules with improved physicochem
Enantioselective fluorination mediated by cinchona alkaloid derivatives/Selectfluor combinations: Reaction scope and structural information for N-fluorocinchona alkaloids
Shibata,Suzuki,Asahi,Shiro
, p. 7001 - 7009 (2007/10/03)
Cinchona-alkaloid/Selectfluor combinations efficiently fluorinate a variety of carbonyl compounds in a highly enantioselective manner to furnish chiral α-fluorocarbonyl compounds. The DHQB/Selectfluor combination is effective for the enantioselective fluo
Expeditious synthesis of 3,4-dihydro-2H-1λ6-benzo[e] [1,2]thiazine 1,1-dioxides
Takeuchi, Yoshio,Liu, Zhaopeng,Satoh, Akira,Shiragami, Tomoki,Shibata, Norio
, p. 1730 - 1733 (2007/10/03)
A novel pathway for the preparation of 3,4-dihydro-2H-1λ6- benzo[e][1,2lthiazine 1,1-dioxides 3 via an orthomethyl lithiation/cyclization reaction of N-acyl-o-toluenesulfonamides 5 is reported. Readily available N-acyl-o-toluenesulfonamides 5 were treated with 2 eq of n-BuLi at -78°C - 0δC to give the corresponding sultams 6 in moderate to good yields. The resulting sultams 6 were converted to saturated sultams 3, which can be considered as one carbon-extended homologues of the Oppolzer suitams 1, in high yields by hydrogenation. Studies on the scope and limitation of this annulation for the preparation of sultams are discussed. Demonstration of the feasibility of using the sultams 3 templates for an electorophilic fluorinating agent is also described.
