Towards New Iron(III) Chelators: Synthesis and Complexing Ability of a Water-Soluble Tripodal Ligand Based on 2,2′-Dihydroxybiphenyl Subunits

Design of Iron chelators: Syntheses and iron (III) complexing abilities of tripodal tris-bidentate ligands

“…The respective pFe of TRENPYPOLS (pFe=23.6) which involves a six-membered chelate ring and of O-TRENSOX (pFe=29.5) corresponding to a five-membered chelate ring may allow a good comparison: the two water soluble chelators have the same atom donor sets, the same spacers and the same connecting groups (Figure 13; Baret et al 2000). In the same way, the tris-catecholate TRENCAMS (pFe=29.6, Thomas et al 1999a, b) and the two tris-2, 2¢ -dihydroxybiphenyl derivatives Lo (pFe=22.8) and Lm (pFe=19.7, Baret et al 1998) allow comparisons between fivemembered and seven-membered chelate rings ( Figure 13). As revealed by the pFe values, the five-membered chelate-rings lead to drastically higher pFe values that can be explain, for an octahedral geometry, by a better minimization of the free energy of the coordination sphere.…”

“…Except for isonicotinoylhydrazones (which exhibit a higher denticity), the bidentate subunits mentioned above involve a five-membered chelating ring size, whose role will be discussed in the physicochemical part of this paper. Pyridinophenol subunits allow a sixmembered coordination ring with the same donor atoms as in the 8-hydroxyquinoline backbone whereas a seven-membered ring chelate can be achieved with o, o¢-dihydroxybiphenyl subunits (Baret et al 1994(Baret et al , 1998. The more usual bidentate groups encountered in tripodal ligands are depicted in Figure 2 often used for comparisons with the more efficient corresponding tripodal compound.…”

Electroactive C2 Symmetry Receptors Based on the Biphenyl Scaffold and Tetrathiafulvalene Units

“…X-ray Structural Data. Crystal data for 3 : C 34 H 34 O 2 S 16 , M r = 987.57, monoclinic, space group P 2 1 / c , a = 11.3922(9) Å, b = 7.8682(5) Å, c = 48.276(7) Å, β = 95.37(1)°, V = 4308.3(8) Å, Z = 4, ρcalc = 1.523 gcm -3 , μ (Mo Kα) = 0.835 mm -1 , F (000) = 2040, crystal dimension = 0.35 × 0.08 × 0.03 mm 3 , θmin = 1.80°, θmax = 25.84°, 15429 reflections collected, 4975 unique ( R int = 0.122), restraints/parameters = 0/209, R 1 = 0.0913 and wR 2 = 0.2047 using 1383 reflections with I > 2σ( I ), R 1 = 0.2591 and wR 2 = 0.2572 using all data, GOF = 0.783, −0.844 < Δρ < 0.900 e Å -3 .…”

“…Due to the ability of the biphenyl unit in transmitting conformational information, considerable interest has been developed around this structure which is often compared to the 1,1‘-binaphthalene-2,2‘-diol (BINOL) unit. Indeed, among other applications, biphenyl 2,2‘-disubstituted derivatives have been used as ligands in catalysis, as synthetic ionophores in the chemistry of biologically active compounds, and in disaccharides recognition . In particular, much progress has been made in the study of conformationally flexible biphenyls ( tropos ) in their application to stoichiometric and catalytic asymmetric reactions .…”

Discovery of Biphenylacetamide-Derived Inhibitors of BACE1 Using de Novo Structure-Based Molecular Design

“…31,32 Subsequent hydrolysis of 31a, followed by Suzuki coupling of the resultant phenylacetic acid 32a with phenylboronic acid using tetrabutylammonium bromide (TBAB), 33 attained the biaryl scaffold 33a in 50% yield. Similarly, the 3-methoxy-4phenyl substituted scaffold 33b was obtained following the same procedure using methyl 4-iodo-3-methoxybenzoate 29b, for which the preparation followed the synthetic route described by Baret et al 34 Intermediates 35 and 36 were synthesized from the conversion of 4-biphenylacetic acid 28 to the methyl ester 34, followed by alkylation at the α-C position using procedures reported by Robichaud et al 35 The alkylated intermediates were subsequently hydrolyzed to give the corresponding biphenylacetic acid intermediates 35 and 36 (Scheme 5).…”