- NBE-Controlled Palladium-Catalyzed Interannular Selective C-H Silylation: Access to Divergent Silicon-Containing 1,1′-Biaryl-2-Acetamides
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A novel palladium-catalyzed interannular selective C-H silylation of 1,1′-biaryl-2-acetamides is described. The combination of palladium catalyst with copper oxidant enables meta- or ortho-selective C-H silylation by employing hexamethyldisilane as a trimethylsilyl source, which relies on the control of NBE derivatives as a switch, thus providing straightforward access to divergent silicon-containing 1,1′-biaryl-2-acetamides.
- Li, Wenguang,Chen, Wenqi,Zhou, Bang,Xu, Yankun,Deng, Guobo,Liang, Yun,Yang, Yuan
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supporting information
p. 2718 - 2722
(2019/04/16)
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- Palladium-catalyzed interannular meta-C-H arylation
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The interannular meta-selective C-H arylation of biaryl-2-trifluoroacetamides using Pd(ii)/norbornene catalysis is reported. The installation of a trifluoroacetyl protecting group to tune their electronic properties and binding ability is essential for in
- Ling, Peng-Xiang,Chen, Kai,Shi, Bing-Feng
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supporting information
p. 2166 - 2169
(2017/02/19)
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- Synthesis and hydrogen bonding capabilities of biphenyl-based amino acids designed to nucleate β-sheet structure
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The syntheses of 3′-(aminoethyl)-2-biphenylpropionic acid (1) and 2-amino-3′-biphenylcarboxylic acid (2) are described. These residues were designed to nucleate β-sheet structure in aqueous solution when incorporated into small, amphiphilic peptides in place of the backbone of the i + 1 and i + 2 residues of the β-turn. N-Benzyl-3′-(2-(benzylamido)ethyl)-2-biphenylpropamide (3) and N-benzyl-(2-benzylamido)-3′-biphenylamide (4) were synthesized and studied as model compounds to investigate the hydrogen-bonding capabilities of residues 1 and 2, respectively. The X-ray crystal structure of 3 indicates that a 13-membered intramolecular hydrogen-bonded ring is formed, while the remaining amide proton and carbonyl are involved in intermolecular hydrogen bonding. Infrared and variable-temperature NMR experiments indicate that, in solution (CH2Cl2), 3 exists as an equilibrium mixture of the 13- and the 15-membered intramolecularly hydrogen-bonded conformers with the 15-membered ring conformer being favored. Amide 4 was shown to exist in solution (CH2Cl2) as an equilibrium mixture of the 11-membered intramolecular hydrogen-bonded ring and a nonbonded conformation. No contribution from the 9-membered hydrogen-bonded ring conformation was observed. The X-ray crystal structure of 4 indicated the absence of intramolecular hydrogen bonding in the solid state.
- Nesloney, Carey L.,Kelly, Jeffery W.
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p. 3127 - 3137
(2007/10/03)
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