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Catalysis Science and Technology
Volumn 1, Issue 9, 2011, Pages 1605-1615
Conjugate addition of arylboronic acids to α,β-unsaturated carbonyl compounds in aqueous medium using Pd(ii) complexes with dihydroxy-2,2′-bipyridine ligands: Homogeneous or heterogeneous nano-catalysis?
Author keywords

[No Author keywords available]
Indexed keywords

CARBONYL COMPOUNDS; LIGANDS; NANOPARTICLES; SODIUM; SODIUM SULFATE; UNSATURATED COMPOUNDS;
EID: 81355123379     PISSN: 20444753     EISSN: 20444761     Source Type: Journal    
DOI: 10.1039/c1cy00214g     Document Type: Article
Times cited : (24)
References (103)
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    • We must note that, parallel to our work, an article describing the conjugate addition of arylboronic acids to enones in water, without the aid of surfactants and under aerobic conditions, has been described by Tsai and co-workers. Their catalytic system was composed of [PdCl2(NH 3)2] and the cationic 2,2′-bipyridine ligand 8 (see discussion)
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    • With the exception of 2a, which is also partially soluble in methanol, dichloromethane and acetone, these complexes only dissolve well in DMSO or DMF Potassium phosphate/KOH buffer solutions were employed for solubility measurements Complex 2d proved to be unstable in DMSO-d6 generating [PdCl2(DMSO-d6)2] and the free ligand 1d. Fortunately, it partially dissolves in CD3NO2 allowing us to run its 1H NMR spectrum in this deuterated solvent (see Experimental Section) Formation of variable amounts of biphenyl and phenol was also observed by GC, as the result of self-coupling and hydrolysis processes, respectively, of the phenylboronic acid (4a) employed in excess
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    • Best results in terms of selectivity (88%) were obtained performing the catalytic reaction in the presence of 5 mol% of the 3,3′-dihydroxy-2, 2′-bipyridine ligand 1a. However, 32 h of heating at 80 °C were still needed to achieve the total consumption of the starting materials For general reviews on nanoparticles stabilization, see
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