Suzuki–Miyaura monocouplings of p-dibromobiphenyl and substituted p-dibromo(penta-p-phenylenes)
作者:Elena Guillén、Jesús Hierrezuelo、Rocio Martínez-Mallorquín、J. Manuel López-Romero、Rodrigo Rico
DOI:10.1016/j.tet.2011.02.025
日期:2011.4
electronic characteristics of the boronicderivative did not affect the selectivity of the reaction. The reaction yields observed were higher at room temperature and when arylboronic pinacol esters were used. These reactions also offer a useful method for the preparation of asymmetrically substituted terphenyls and hexa-p-phenylenes, giving good yields.
Synthesis of dihydroxyoligophenylenes containing π-deficient or π-excess hetero-aromatic rings and their solvatochromic behavior
作者:Isao Yamaguchi、Kenji Seo、Yukari Kawashima
DOI:10.1016/j.tet.2010.06.087
日期:2010.8
Dihydroxyoligophenylenes (HO-ArPh(m)-OHs) with 9,9-dihexy1-2,7-fluorene (Ar=Flu), 2,5-dioctyloxy-1,4-benzene (Ar=Dob), pyridine (Ar=Py), or thiophene (Ar=Th) rings were synthesized by the Suzuki coupling reaction. Absorption maxima (lambda(max)) of HO-ArPh(m)-OHs shifted progressively toward long wavelengths due to the expansion of the it-conjugation system with an increase in the number of benzene rings. Deprotonation of the OH groups of HO-ArPh(m)-OHs by treatment with NaH caused a bathochromic shift of lambda(max). The bathochromic shift of the deprotonated species increased with the donor numbers (DNs) of the solvents. The emission peak positions of NaO-ArPh(m)-ONas depended on the DNs of the solvents; therefore, the emission color could be tuned by changing the solvent. (C) 2010 Elsevier Ltd. All rights reserved.
Synthesis of oligophenylenes containing hydroxyl group and their solvatochromic behavior
作者:Isao Yamaguchi、Kazuyuki Goto、Moriyuki Sato
DOI:10.1016/j.tet.2009.02.073
日期:2009.5
Oligo(p-phenylene)s containing hydroxyl group(s), namely, OPP(n)-OH (n=3, 4, and 5; it denotes the number of benzene rings), HO-OPP(3)-OH, and 1,3,5-tri(4-biphenyl)phenol TBP-OH were synthesized in high yields by the Suzuki coupling reaction. Absorption maxima (lambda(max)s) of OPP(n)-OHs shifted progressively toward long wavelengths due to the expansion of the pi-conjugation system with an increase in the number of benzene rings. Deprotonation of the OH group of OPP(n)-OHs by treatment with NaH caused a bathochromic shift of lambda(max). The bathochromic shift of the deprotonated species increased with the donor numbers (DNs) of the solvents. The emission peak positions of OPP(n)-OH and OPP(n)-ONa depended on the DN of the solvents; that is, the emission color could be tuned by changing the solvent. (C) 2009 Elsevier Ltd. All rights reserved.