- Synthesis of arylglycine and mandelic acid derivatives through carboxylations of α-amido and α-acetoxy stannanes with carbon dioxide
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Incorporation reactions of carbon dioxide (CO2) with N-Boc-α-amido and α-acetoxy stannanes were developed using CsF as a mild tin activator. Monoprotected α-amido stannanes could be used, and the corresponding arylglycine derivatives were obtained in moderate-to-high yields under 1 MPa (10 atm) of CO2 pressure. α-Acetoxy stannanes also underwent carboxylation to afford mandelic acid derivatives in excellent yields under ambient CO2 pressure. Both transformations enabled the synthesis of α-tertiary and α-quaternary carboxylic acid derivatives. In addition, the chirality of (S)-N-tert-butylsulfonyl-α- amido stannanes was transferred with up to 90% inversion of configuration at 100 °C.
- Mita, Tsuyoshi,Sugawara, Masumi,Hasegawa, Hiroyuki,Sato, Yoshihiro
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experimental part
p. 2159 - 2168
(2012/06/01)
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- One-pot synthesis of α-amino acids from imines through CO2 incorporation: An alternative method for strecker synthesis
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Itas a gas: A novel one-pot process for the synthesis of α-amino acids from imine equivalents using CO2 gas as a carbon source has been developed. This reaction was made possible by the reagent combination of TMSSnBu3 and CsF (see scheme). Three successive reactions (imine formation, stannylation, and carboxylation) proceeded in the same flask under these conditions to give products in up to 79 % yield. Boc=tert-butoxycarbonyl, TMS=trimethylsilyl.
- Mita, Tsuyoshi,Chen, Jianyang,Sugawara, Masumi,Sato, Yoshihiro
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supporting information; experimental part
p. 1393 - 1396
(2011/04/22)
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- UREA DERIVATIVE, PROCESS FOR PRODUCING THE SAME, AND USE
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The present invention provides a urea derivative or a salt thereof, which is useful as a therapeutic agent for thrombosis. The derivative is represented by Formula (I): [Chemical formula I] wherein Cy is an aromatic hydrocarbon group which may be substituted or an aromatic heterocyclic group which may be substituted; R1 is a hydrogen atom or a hydrocarbon group which may be substituted; V is -C(O)-, -S(O)-, or -S(O)2-; W is -N(R2)-, -O-, or a bond (wherein R2 is a hydrogen atom or a hydrocarbon group which may be substituted); X is alkylene which may be substituted; Y is -C(O)-, -S(O)-, or -S(O)2-; Z is a bond, a chain hydrocarbon group which may be substituted, or -N=; ring A is a non-aromatic nitrogen-containing heterocyclic ring which may be substituted; ring B is a nitrogen-containing heterocyclic ring which may be substituted; and [Chemical formula 2]------ ̄?,?------? are each independently a single bond or a double bond; provided that R1 may be bonded to R2 to form a non-aromatic nitrogen-containing heterocyclic ring and that R2 may be bonded to a substituent of X to form a non-aromatic nitrogen-containing heterocyclic ring which may be substituted.
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Page/Page column 63
(2010/11/23)
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