Study 6.26 Biology photoactivatable compounds

Case Study 6.27 Supercritical C02 chemistry - photo-Fries reaction 

Supercritical solvents, compounds at a temperature and pressure above their thermodynamic critical points, are interesting reaction media because their properties, 

The decarbonylation reaction can also be accompanied by oxidative addition, an insertion of the metal into a covalent bond. For example, the tris(dimethylpyrazolyl)borato 

The great structural diversity of nitrogen-containing compounds, ranging from imines and azo compounds to nitro compounds and amines, is connected to its diverse but characteristic photochemical reactivity (Table 6.15). The presence of a lone electron pair on nitrogen in chromophores containing an N=X bond (X=N, C) indicates that both the n,Jt and n,n excited states can be involved in the reactions. While E Z isomerization is a typical reaction for both imines and azo compounds (entry 1), the latter chromophores may additionally 

Photofragmentation is the principal primary process of excited aliphatic nitro compounds subsequently producing N02 and the corresponding radicals (entry 8), which may recombine to form nitrites. The excited nitroalkanes or nitroarenes can also be photoreduced in the presence of a hydrogen-atom donor (entry 9). 

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