An efficient protocol to synthesize unsymmetrical triphenylenes from electron-rich biphenyls and diaryliodoniumsalts via Cu catalysis was developed. A variety of unsymmetrical triphenylenes with diversified functional groups were synthesized according to this method. This transformation went through multiple direct C–H arylations from easily produced starting materials with high step-economy. The
Efficient Suzuki-Miyaura mono-arylation of symmetrical diiodo(hetero)arenes
作者:Alexander Sapegin、Mikhail Krasavin
DOI:10.1016/j.tetlet.2018.04.015
日期:2018.5
A reliable protocol for converting 1,4-diiodo-2,3,5,6-tetrafluorobenzene into 1-(hetero)aryl-4-iodo-2,3,5,6-tetrafluorobenzene derivatives has been lacking in the literature. We have identified optimal conditions to achieve this conversion in good yields and have minimized formation of the bis-coupling product. The newly identified protocol involving the use of a syringe pump has been extended to other symmetrical diiodo(hetero)arenes. (C) 2018 Elsevier Ltd. All rights reserved.
Synthesis of tetrahydroxybiphenyls and tetrahydroxyterphenyls and their evaluation as amyloid-β aggregation inhibitors
作者:Craig B. Stevens、James M. Hanna、Robin K. Lammi
DOI:10.1016/j.bmcl.2013.01.076
日期:2013.3
3,3',4,4'-Tetrahydroxybiphenyl and three isomeric 3,3 '',4,4 ''-tetrahydroxyterphenyls with varying geometries around the central phenyl ring have been synthesized and evaluated for their in vitro activity against aggregation of Alzheimer's amyloid-beta peptide (A beta). Results from Congo red spectral-shift assays reveal that all four compounds successfully inhibit association of A beta monomers. For the tetrahydroxyterphenyls, efficacy varies with linker geometry: the ortho-arrangement affords the most successful inhibition and the para-geometry the least, perhaps due to differing abilities of these compounds to bind A beta. Of the four small molecules studied, 3,3',4,4'-tetrahydroxybiphenyl is the most effective inhibitor, reducing A beta aggregation by 50% when present in stoichiometric concentrations. (C) 2013 Elsevier Ltd. All rights reserved.