Gold catalysis in the reactions of 1,3-dicarbonyls with nucleophiles

Arcadi, Antonio; Bianchi, Gabriele; Giuseppe, Sabrina Di; Marinelli, Fabio

doi:10.1039/b210165c

Cited by 178 publications

(93 citation statements)

References 17 publications

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“…In a chemical process catalysts are used in order to reduce energy requirements and to make reactions happen more efficiently 9 . Another benefit of using a catalyst is that generally small amounts are required to have an effect.…”

Section: Catalysismentioning

confidence: 99%

Applications of Green Chemistry in Sustainable Development

Dhage¹,

Shisodiya²

2013

Int. Res. J. Pharm.

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Chemistry is really very helpful to us as its applications are used worldwide for several purposes. We cannot really imagine a world without chemistry and its applications such as medicines. However, we should now concentrate on green chemistry or sustainable chemistry, which refers to reducing or stopping the damage done to the environment around us. Hence, green chemistry could include anything from reducing waste to even disposing of waste in the correct manner. Another way to save the environment through sustainable chemistry is to make use of renewable food stocks. Yet another good move is to make use of catalysts in experiments rather than using stoichiometric reagents. Chemical derivatives must be avoided as far as possible in any type of application as they often prove to be harmful. All chemical wastes should be disposed of in the best possible manner without causing any damage to the environment and living beings. We have to develop materials that will aid in the infusion of green chemistry into the curriculum such as green chemistry laboratory experiments and short courses on green chemistry. This article presents a brief description on green chemistry principles and its developments.

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Section: Catalysismentioning

confidence: 99%

Applications of Green Chemistry in Sustainable Development

Dhage¹,

Shisodiya²

2013

Int. Res. J. Pharm.

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“…They observed that an amine 89 does not intermolecularly add to the alkyne in 88 but that Na[AuCl4]•H2O catalyses the condensation of the amine with a carbonyl group (62) and then the intramolecular Nnucleophile in 91 reacts with the alkyne and produces the pyrrole 92, Figure 33. On the other hand, the corresponding Pd-catalyst Na2[PdCl4] does not catalyse the condensation, and the intramolecular addition of the oxygen atom of the aldehyde group gives the oxygen-heterocycle 90.…”

Section: Figure 32mentioning

confidence: 99%

“…A new synthesis of quinolines nucleophiles was developed (62). Thus, with amines 94 ␤-enaminones 95 could be obtained under mild conditions in high yields, Figure 34.…”

Section: Figure 35mentioning

confidence: 99%

Homogeneous catalysis by gold

2004

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A comprehensive overview in the field of homogeneous catalysis by gold is given and the basic principles are discussed. It is also highlighted where homogeneous gold catalysts are already superior to other catalysts and where future possibilities for advantageous use of homogeneous gold catalysts exist.For a long time, gold was considered to possess only low catalytic activity ("catalytically dead") and therefore only its stoichiometric co-ordination and organo-metallic chemistry was investigated intensively. Even in the 19th century it was quite popular to characterize precious alkaloid bases after their troublesome isolation from natural sources as tetrachloroaurates (1,2).Since then, a change of paradigm has taken place (3). Among the numerous applications for gold, its use as a catalyst, albeit not yet consuming large amounts of this metal, has attracted much attention. Overall, in the chemical databases ca. 230,000 papers on gold can be found, of which about 9,000 deal with gold catalysis (from the SciFinder database in October 2003). The field of gold catalysis is dominated by heterogeneous catalysts, while homogeneous catalysts still represent the much smaller part (about 100 hits). Still, a significant amount of different homogeneous gold-catalysed reactions is known and basic principles can be deduced from them.In this article only publications in which gold is unambiguously the site of the catalysis reaction will be covered. This, for example, excludes the use of some mixed metal clusters and mixed metal colloids. BackgroundHomogeneous catalysis includes all reactions in which the substrate(s) and the catalyst are in the same state. As there exists only a limited number of highly volatile gold compounds, most of these reactions are conducted in the liquid phase with either liquid or dissolved substrate(s) and a dissolved catalyst. Homogeneous catalysis in the solid state, a part of the solvent-free reactions (4) that are nowadays quite popular in the field of green chemistry, has not been explored with gold yet (with the exception shown in Figure 31)! In this context, the non-toxicity of gold, which helps to avoid any environmental problems, is also of importance.The catalyst itself promotes a chemical reaction, a process in which chemical compounds (the substrates) are converted to other chemical compounds (the products), to proceed under milder reaction conditions (lower temperatures, lower pressure, lower concentrations of the substrates, higher or different selectivity). As the catalyst is not consumed, a catalytic amount is sufficient -but this is often a matter of debate: for some scientists 20 mol% of 'catalyst' are still catalytic, while others may consider this to be a substoichiometric reaction and accept only 0.001 mol% or less as catalytic.Two motives drive the desire to produce a chemical reaction: The use of gold as a catalyst is desirable when it has a similar activity as for a more expensive catalyst, when it shows a higher activity or a higher selectivity than less expensive catalysts...

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“…Condensation of carbonyl compounds and amines mediated by acid catalysts is a simple methodology for synthesis of enamino esters. Diversified acid catalysts such as metal triflates 4 , perchlorates 5 , InBr 6 , CoCl 2 7 , silica supported mineral acid 8 , BF 3 *Et 2 O 9 , silver nanoparticles 10 , copper nanoparticles 11 , gold salts 12 and Zn(OAc) 2 13 have been used in the synthesis of β-enaminones and enamino esters. The above catalysts are either expensive or moisture sensitive or nonrecyclable or require harsh reaction conditions.…”

Section: Introductionmentioning

confidence: 99%