Triarylbismuthanes as Threefold Aryl-Transfer Reagents in Regioselective Cross-Coupling Reactions with Bromopyridines and Quinolines
作者:Maddali L. N. Rao、Ritesh J. Dhanorkar
DOI:10.1002/ejoc.201402455
日期:2014.8
Cross-coupling studies using bromopyridines and bromoquinolines with triarylbismuths as threefold coupling reagents in substoichiometric amounts under Pd-catalysed conditions are disclosed. The reactivity was high with both mono- and dibromopyridyl substrates, and mono- and bis-couplings were carried out regioselectively. A library of monoaryl and diaryl pyridines was formed in high yields. A one-pot
Synthesis of analogs of amrinone: 4-(3,4-Disubstitutedphenyl)pyridines and derivatives thereof
作者:Baldev Singh、George Y. Lesher
DOI:10.1002/jhet.5570280416
日期:1991.6
4-(3,4-Dimethoxyphenyl)pyridine (5c) prepared by the coupling of 3,4-dimethoxyphenyldiazonium chloride with pyridine was converted to 4-(4-pyridinyl)benzene-1,2-diol (6c) by treating with hydrobromic acid. Diazotization of 4-(4-pyridinyl)benzeneamine (7) and 3-(4-pyridinyl)benzeneamine (12) gave the corresponding phenols 8 and 13 which were nitrated to give 2-nitro-4-(4-pyridinyl)phenol (9) and 2-
Boronate esters that contain N-donor groups are self-complementary structures, which can assemble by means of dative boron–nitrogen bonds to form macrocycles or polymers. Herein, we describe the synthesis of dioxaborinanes and benzodioxaboroles containing pyridylsidechains. In the solid state, the dioxaborinanes were found to exist predominantly as monomers. Upon crystallization, aggregation into
Cross-coupling study of iodo/chloropyridines and 2-chloroquinoline with atom-economic triarylbismuth reagents under Pd-catalysis
作者:Maddali L.N. Rao、Ritesh J. Dhanorkar
DOI:10.1016/j.tet.2014.11.036
日期:2015.1
This study describes the palladium-catalyzed couplings of iodopyridines, chloropyridines, and chloroquinoline with atom-economic BiAr3 reagents in sub-stoichiometric loadings. Mono-arylations of iodo and chloropyridines produced arylpyridines in high yields. The couplings addressed with dihalopyridines have afforded chemo- and regio-selective coupling products. Arylations of 2-chloroquinoline with different triarylbismuth reagents demonstrated fruitful coupling reactivity under the established conditions. This sumptuous study demonstrates the remarkable cross-coupling reactivity of iodo/chloropyridines and chloroquinoline with triarylbismuth reagents. (C) 2014 Elsevier Ltd. All rights reserved.
Ti(IV)-Centered Dynamic Interconversion between Pd(II), Ti(IV)-Containing Ring and Cage Molecules
作者:Shuichi Hiraoka、Yoko Sakata、Mitsuhiko Shionoya
DOI:10.1021/ja803115j
日期:2008.8.1
Heteronuclear, supramolecular ring and cage complexes have been constructed from a pyridyl catechol ligand, TiO(aca)(2), and PdCl(2)(CH(3)CN(2)). These two complexes are quantitatively interconvertible, in which Ti(4+) centered coordination changes take place between a well-known Ti(catecholato)(3) and a newly established TiH(catecholato)(2)(acetylacetonato) structures. The Ti(4+)-centered structural changes arise from the changes in the component fraction basicity condition.