Bonnemann synthesis

Bischler-Napieralski synthesis (isoquinoline) 413 Bltimlein-Lewy synthesis (oxazole) 172 B oekelheide reaction 362 Bonnemann synthesis (pyridine) 373 Bohlmann-Rahtz synthesis (pyridine) 369 Borsche synthesis (cinnoline) 494 von Braun degradation 432 Brederek synthesis... 

Another particularly significant breakthrough results from the direct synthesis of pyridine and of its derivatives by Co oligomerization of two molecules of acetylenes with a nitrile (Bonnemann synthesis [4]). The potentialities of the Bonnemann reaction are well illustrated by its application to the synthesis of heterocyclic systems, a particularly illustrative example being the synthesis of vitamine B6 [5g]. 

A typical example of such an application is the one step synthesis of pyridines directly from acetylenes and nitriles (Bonnemann synthesis [4]). 

The concept of using colloids stabilized with chiral ligands was first applied by Bonnemann to hydrogenate ethyl pyruvate to ethyl lactate with Pt colloids. The nanoparticles were stabilized by the addition of dihydrocinchonidine salt (DHCin, HX) and were used in the liquid phase or adsorbed onto activated charcoal and silica [129, 130]. The molar ratio of platinum to dihydrocinchonidine, which ranged from 0.5 to 3.5 during the synthesis, determines the particle size from 1.5 to 4 nm and contributes to a slight decrease in activity (TOF = l s ). In an acetic acid/MeOH mixture and under a hydrogen pressure up to 100 bar, the (R)-ethyl lactate was obtained with optical yields of 75-80% (Scheme 9.11). 

Franco, E.G., Neto, A., Linardi, M., and Arico, E., Synthesis of electrocalysts by the Bonnemann method for the oxidation of methanol and the mixture of H2/CO in a proton exchange membrane fuel cell, J. Braz. Chem. Soc., 13, 516, 2002. 

What are the advantages of Bonnemann s method of colloidal nanoparticle synthesis ... 

Bonnemann, H., Brijoux, W., Organocobalt-Catalysed Synthesis of Pyridines,... 

H. Bonnemann, and W. Brijoux, Cyclomerization of Alkynes, in Transition Metal for Organic Synthesis, Second Ed. (Eds. M. Beller and C. Bolm, Wiley-VCH, Weinheim, 2004, Vol. 1, Chap. 2.8). 

Bojarski, I. T., Mokrosz, I. L., Barton, H. J., Paluchowska, M. H., Recent Progress in Barbituric Acid Chemistry, 38, 229. Bonnemann, H., Brijoux, W., Organocobalt-Catalysed Synthesis of Pyridines,... 

For additional related examples see H. BOnnemann and R. Brinkmann, Synthesis, 1975, 600. 

Fig. 1.1 Electrosteric (i.e. electrostatic with the halide anions located between the positively charged NP surface and the tetra-N-butyl ammonium cations and steric with the tetra-N-butyl ammonium cation) stabilization of metal NPs obtained by reduction of a metal chloride salt in the presence of a tetra-N-butyl ammonium cation (Bonnemann-type synthesis of Eq. (1.1)). The presence of...

Caruso reported the synthesis and stabilization of PdNPs using Na2PdCl, and (4-dimethylamino)pyridine [8d]. Since the 1980s, metal salts, a molecular stabilizer and a reductant [4—7, 11] have been used by Bonnemann, as represented in Eq. (1.1) [6]. 

The radiation method was described by Rogninski and Schalnikoff for the first time and is based on condensation of the metal atoms after collision [154]. Reetz et al. prepared nanoparticles via electrochemical synthesis [155]. Salt reduction was developed by Bonnemann to obtain mono- and bi-metallic nanoparticles in solution [156]. Salt reduction is the most widely practised method for the synthesis of colloidal metal suspensions. Faraday synthesised gold particles by the reduction of HAuCb [157]. 

One step methods. PtRuMo/C catalysts obtained by the impregnation manner revealed that the addition of a relatively small amount of Mo results in an electrocatalyst with a higher activity in CO or methanol electrooxidation than with the PtRu/C system. Moreover, Benker et al studied the effect of molybdenum precursor, and the physico-chemical characterization indicated that only traces of molybdenum were present in the samples when Mo (CO) 6 was used for the synthesis, while ammonium molybdate was an appropriate precursor for the synthesis of PtRuMo/C catalysts. On the other hand, a colloidal method developed by Bonnemann et alP was used to prepare carbon supported PtRuMo nanoparticles and established that this method provided a better tool for synthesizing PtRuMo (1 1 1) nanoparticles deposited on a carbon substrate, being more... 

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