Singlet oxygen, generators

Using a single-channel chip micro reactor, singlet oxygen is generated by photochemical means in presence of catalytic amounts of Rose Bengal [21]. By [4 -i- 2] cycloaddition of this oxygen species to a-terpinene, the product ascaridole is obtained. 

AUylic alcohols constitute an alternative valuable source for the preparation of S-hydroperoxyalcohols suitable for peroxyacetalization to 1,2,4-trioxanes. A number of 3-alkyl-substituted allyl alcohols undergo a highly regio- and stereoselective ene-reaction with singlet oxygen to generate the corresponding /l-hydroperoxyalcohols. ... 

Excited 0(21D) atoms are metastable and have very long life in the thin upper atmosphere. The atoms are deactivated by energy transfer on Collision with oxygen molecules generating singlet molecular oxygen,... 

Reactions with Singlet Oxygen. Singlet oxygen generated by photosensitization... 

In the present work, we performed the hydroperoxidation of unsaturated polymers as EPDM or polyoctenamer by using singlet oxygen photo-generated at 365 nm by anthracene / O2. The resulting hydroperoxidized polymer (POOH) was then decomposed by UV irradiation (X > 300 nm) in the presence of unsaturated monomers or nitroxyl radicals. The efficiency of these new grafted polymers as new photo- and thermo-stabilizers will be finally demonstrated. 

Recently, however, both Foote212 and Corey213 have studied the reactions of oxygen molecules generated in excited singlet states. In a number of cases these give the same products with representative substrates as obtained in photosensitized oxidations. 

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