Green synthetic methods

Albini, A. and Fagnoni, M. (2008) Photochemistry as a green synthetic method, in New Methodologies and Techniques for a Sustainable Organic Chemistry (eds A. Mordini and F. Faigl), Springer Science Business Media B.V., pp. 279-293. 

This method made use of equimolar amounts of the reagents (while an excess of aldehyde was required in the corresponding thermally initiated reactions) and avoided the use of foul-smelling auxiliaries, such as thiols. These facts qualify the reaction as a green synthetic method. In addition, the atom... 

The "Green synthetic reactions" module provides technical information on green synthetic methods. 

Recent interest toward aminochromene synthesis is connected with attempts to design some new green synthetic procedures. As a rule, these syntheses are conducted by three-component method from the corresponding aldehydes, nitriles, and phenols. Aminochromenes have been obtained on refluxing in aqueous media in the presence of the quaternary ammonium salts trimethylcetylammonium chloride (01T1395) and... 

Keglevich, G., Kerenyi, A., Sipos, M., Ujj, V., Mako, A., Csontos, L, Novak, T., Bak6, R, and Greiner, I. 2007. Green chemical approaches and tools in the development of environmentally friendly synthetic methods. Periodica Polytechnica Chemical Engineering, 51 53-56. 

Recently, Mg and Be compounds have been used in alloys with ZnSe to make blue and green semiconductor lasers. Bulk growth by zone melting and molecular beam epitaxy (MBE) ° has been used. In these cases, good semiconductor material has been obtained dilution with group IIB compounds may be responsible. However, growth of pure MgS in very thin films on ZnSe has been achieved the epitaxial orientation effect of the substrate results in a tetrahedral cubic (sphalerite or zinc-blende) structure. It is likely that improvements in these materials will take place at a rapid rate, driven in part by applications and in part by newer, cleaner synthetic methods. 

Synthesizing organic molecules under mild conditions and with the minimal environmental impact is one of the main targets of green chemistry. Traditional synthetic methods often involve rather harsh conditions. As an example, many methods for carbon-carbon bond formation involve an enolate as the key intermediate and thus are carried out under strongly basic conditions and/or require the introduction of activating groups, which leads to a poor atom economy. 

Certainly, for most synthetic chemists the concern about the green aspects is nowadays present in their search for new synthetic methods. Green aspects are then put in evidence in the corresponding publications. Most often, however, this is apphed to any method discovered that allows making a compound to react in a way that is either impossible by conventional chemistiy, or possible only under severe conditions. This is something that is new and can be added to the choice of methods a synthetic chemist has available. Typically, a catalyst is used that makes the reaction occur under milder conditions. 

The teaching was divided in basic themes i.e Atom economy. Industrial Processes, Alternative Solvents, New Feedstocks and Products, New Reactions and New Synthetic Methods. In addition topics related to current research in Green Chemistry were addressed with the aim to familiarize the students with the strategies behind the planning and designing of efficient and "greener synthetic routes. 

H. G. Davies, R. H. Green, D. B. Kelly, S. M. Roberts in Best Synthetic Methods Biotransformations in Preparative Organic Chemistry, pp 99-155, Academic, New York 1989. 

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