Photochemistry in synthesis: Where, when, and why*
Stefano Protti1, Daniele Dondi1,2, Maurizio Fagnoni1, and Angelo Albini1
1Department of Organic Chemistry, University of Pavia, via Taramelli 10, 27100 Pavia, Italy; 2INCA Consortium, Via delle Industrie, 21/8-30175 Marghera (VE), Italy
Abstract: A series of photochemical reactions are assessed under the environmental aspect by using Eissen and Metzger's EATOS (environmental assessment tool for organic syntheses) method and are compared with strictly analogous thermal processes. These include C-C bond-forming reactions (arylation and alkylation) and selective oxidation and reduction reactions. In most cases, the photochemical method is experimentally simpler and less expensive than the thermal alternative. A disadvantage is that photochemical reactions are carried out in rather dilute solution, and this factor gives by far the main contribution to the assessment. However, if the solvent is recovered, the photochemical reaction is more environment-friendly.
Keywords: green chemistry; photochemistry; C-C bond formation; reduction; oxidation.
*Pure Appl. Chem. 79, 1831-2100. An issue of reviews and research papers based on lectures presented at the 1st International IUPAC Conference on Green-Sustainable Chemistry, held in Dresden, Germany, 10-15 September 2006.