Singlet oxygen 1,3-dienes, photooxygenation

Mechanism of the Singlet Oxygen Diene Photooxygenation Theoretical Models Experimental Results. .. 25-2... 

Singlet oxygen reacts with many carbocyclic 1,3-dienes to form the corresponding bridged endoperoxides, which can be further transformed into miscellaneous polyoxy functionalized carbocycles . The rate of photooxygenation of n-cyclic 1,3-dienes is gradually decreasing in the order n = 5) >6>7 8 While the rate... 

Photooxygenation of l,l-dimethyl-2,3,4,5-tetraphenylsilole was studied by Sato and coworkers, and Sakurai and coworkers . The intermediate endoperoxide was produced by 1,4-addition of singlet oxygen to the cyclic diene, leading to cis- and frawi-dibenzoylstilbenes in addition to the major product (1 1.45), 3,3-dimethyl-l,5,6,7-tetraphenyl-2,4-dioxa-3-silabicyclo[3.2.0]heptene (Scheme 24). Under the same conditions, the photooxygenation of l-methyl-l-vinyl-2,3,4,5-tetraphenylsilole leads to analogous... 

The triplet excited state of C q is formed with a quantum yield close to unity, and by energy transfer to molecular oxygen, it produces large quantities of singlet oxygen (Equation 28.2). This useful photochemical property makes Qo a potent sensitizer for the mild photooxygenation of simple alkenes and dienes. ... 

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