Facilitating [2+2] Photocycloadditions by Promoting Oxygen Tolerance and Substrate Activation in Water.

Micellar photocatalysis has been used to overcome oxygen quenching and enable a [2+2] photocycloaddition through triplet-energy transfer in water under aerobic conditions. The cheap and commercially available self-assembling sodium dodecyl sulfate (SDS) micelles were found to increase the oxygen tolerance of a typically oxygen-sensitive reaction. Furthermore, the use of the micellar solution was found to activate α,ß-unsaturated carbonyl compounds to energy transfer and allow [2+2] photocycloadditions to take place. Our preliminary studies of micellar effects on energy-transfer-based reactions demonstrate the reaction between α,ß-unsaturated carbonyl compounds and activated alkenes in a mixture of SDS, water and [Ru(bpy)3 ](PF6 )2 .