Photoassisted reactions olefins

The photoassisted oxidation of olefins and cycloolefins [28], [30] in the presence of p-oxobis[(tetraphenylporphyrinato)iron(III)] [31], figure 5, belongs to such photoassisted reactions as described by equation (5). Here, the catalytically active iron(IV) species reacts in the ground state. The nominal catalyst is regenerated by dissolved oxygen immediately after the epoxidation of the olefin. It has to be activated by light again in order to start the next cycle. 

Cu(I) triflate has been used as an olefin cycloaddition photoassistance agent as in reactions (42) and (43).127 Detailed study of reaction (43) shows that it is very likely that it is photoexcitation of a Cu(alkene)2 complex that results in the dimerization.127) This provides a second good example of the possible utility of transition metal photoassistance involving reactions between coordinated ligands. The nature of the excited state leading to reactions (40)-(43) is not known. 

Geometrical Photoisomerizations. in this section geometrical photoisomerization reactions of OTM compounds are considered. Recent accounts of photoinduced rearrangements of coordinated ligands and OTM complex photoassisted isomerization of olefins, dienes, and so on are available elsewhere (3,4,91). 

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