- Metal-free synthesis of biaryls from aryl sulfoxides and sulfonanilides via sigmatropic rearrangement
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Treatment of aryl sulfoxides and sulfonanilides with trifluoroacetic anhydride resulted in the dehydrative metal-free construction of the corresponding unsymmetrical biaryls. The reaction would proceed via (1) the activation of aryl sulfoxide with the anhydride, (2) interrupted Pummerer reaction of the resulting arylsulfonium with sulfonanilide, (3) [3,3] sigmatropic rearrangement to cleave the transient S–N bond and to form the prospective biaryl C–C bond, and (4) global aromatization. The choice of the amino protecting group is crucial, and only N-sulfonylanilines, i.e., sulfonanilides, could participate in the formation of biaryls.
- Yoshida, Akira,Okamoto, Koichi,Yanagi, Tomoyuki,Nogi, Keisuke,Yorimitsu, Hideki
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- Palladium-catalyzed homo-coupling of heteroarylsulfoniums via borylation/Suzuki-Miyaura coupling sequence
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Palladium-catalyzed homo-coupling of heteroaryldimethylsulfoniums proceeds in the presence of bis(pinacolato)diboron and a base to yield biheteroaryls. The homo-coupling involves palladium-catalyzed borylation and the subsequent Suzuki-Miyaura coupling. As the sulfoniums were able to be prepared in situ from the corresponding heteroaryl sulfides and methyl triflate, one-pot transformations of heteroaryl sulfides into the homo-coupling products were executed. Furthermore, a facile synthesis of a highly substituted 2,2'-bibenzofuran was accomplished with a combination of Pummerer-type synthesis of 2-benzofuryl sulfide and the present homo-coupling.
- Minami, Hiroko,Nogi, Keisuke,Yorimitsu, Hideki
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p. 998 - 1007
(2019/04/26)
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- Structure-activity relationship (SAR) of the α-amino acid residue of potent tetrahydroisoquinoline (THIQ)-derived LFA-1/ICAM-1 antagonists
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This letter describes the structure-activity relationship (SAR) of the 'right-wing' α-amino acid residue of potent tetrahydroisoquinoline (THIQ)-derived LFA-1/ICAM-1 antagonists. Novel (S)-substituted heteroaryl-bearing α-amino acids have been identified
- Zhong, Min,Hanan, Emily J.,Shen, Wang,Bui, Minna,Arkin, Michelle R.,Barr, Kenneth J.,Evanchik, Marc J.,Hoch, Ute,Hyde, Jennifer,Martell, Jose R.,Oslob, Johan D.,Paulvannan, Kumar,Prabhu, Saileta,Silverman, Jeffrey A.,Wright, Jasmin,Yu, Chul H.,Zhu, Jiang,Flanagan, W. Mike
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scheme or table
p. 307 - 310
(2011/02/27)
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- MODULATORS OF CELLULAR ADHESION
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The present invention provides compounds having formula (I): and pharmaceutically acceptable derivatives thereof, wherein R1-R4, n, p, A, B, D, E, L and AR1 are as described generally and in classes and subclasses herein, and additionally provides pharmaceutical compositions thereof, and methods for the use thereof for the treatment of disorders mediated by the CD11/CD18 family of cellular adhesion molecules (e.g., LFA-1).
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Page/Page column 98
(2010/02/11)
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- Biotransformation of organic sulfides. Part 12. Conversion of heterocyclic sulfides to chiral sulfoxides by Helminthosporium sp. NRRL 4671 and Mortierella isabellina ATCC 42613
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The enantioselective oxidation of a series of heterocyclic prochiral sulfides to chiral sulfoxides has been examined using the fungal biocatalysts Helminthosporium species NRRL 4671 and Mortierella isabellina ATCC 42613. Methylthiofuranyl and -thiophenyl
- Holland, Herbert L.,Turner, Carl D.,Andreana, Peter R.,Nguyen, Doan
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p. 463 - 471
(2007/10/03)
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- An analysis of substituent effects on 1H and 13C NMR parameters of substituted furans. Linear free energy relationships and PM3 semiempirical calculations
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Forty five furans have been obtained in a synthetic project designed to evaluate monothiosubstituted furans as potential food flavourings. A full NMR (1H and 13C) study and PM3 molecular orbital semiempirical calculations have been carried out. Substituent-induced chemical shifts (SCS) for six and nine substituents at the 2- and 3-positions have been calculated and a separation of inductive and resonance effects of these substituents has been proposed. Finally, a linear correlation between the net atomic charges localized at ring carbons and their 13C NMR chemical shifts has been established.
- Alvarez-Ibarra, Carlos,Quiroga-Feijoo, Maria L.,Toledano, Emilio
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p. 679 - 689
(2007/10/03)
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