Adipic green routes

Sato, K., Aoki, M., Noyori, R. (1998) A Green Route to Adipic Acid Direct Oxidation of Cyclohexenes with 30 Percent Hydrogen Peroxide. Science, 281, 1646-1647. 

A Green Route to Adipic Add Direct Oxidation of Cyclohexenes with 30 Percent Hydrogen Peroxide... 

Sato, K., M. Aoki, and R. Noyori (1998) A green route to adipic acid Direct oxidation of cyclohexenes with 30 percent hydrogen peroxide. Science 281,1646-1647. 

The interest in 1,3-butadiene hydroformylation is the atom-efficient green route for producing /1, y-unsaturated aldehyde and 1,6-hexanedial (adipaldehyde), which is a valuable precursor for producing a-caprolactam and adipic acid/hexamethylene-1, 6-diamine (HMDA) as key monomers in nylon-6 and nylon-6,6 manufacture. 

Recently, Ryoji Noyori (2001 Nobel Prize in Chemistry) and coworkers at Nagoya University in Japan developed a "green" route to adipic acid, one that involves the oxidation of cyclohexene by 30% hydrogen peroxide catalyzed by sodium tungstate, Na2W04 ... 

Figure 7.5 A green route to adipic acid by oxidation with aq. H2O2.

The new synthetic route to ibuprofen is an important example of how ideas of green chemistry can influence for the better the industrial synthetic methods used, not only from the point of view of economic efficiency, but also by introducing more effective methods of science and technology. Improved methods of synthesis for hexan-l,6-dioic acid (adipic aid) and cis-butenediol acid (maleic anhydride) - important for the industrial synthesis of nylon and polyesters respectively - are two other examples of the impact of a greener synthetic approach to industrial chemistry. 

The high demand for nylon has stimulated the development of several ingenious cheap syntheses of the monomeric precursors. Thus, hexanedioic (adipic) acid is currently produced from benzene by three different multistep routes, all culminating in the last step in the salt-catalyzed oxidation of cyclohexanol (or cyclohexanol/cyclohexanone mixtures) with nitric acid. A green approach was disclosed in 2006 by chemists at Rhodia Chimie, France, in which air is used as the oxidizing agent instead of the toxic and corrosive (and more expensive) HNO3. 

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