Visible Light Copper Photoredox-Catalyzed Aerobic Oxidative Coupling of Phenols and Terminal Alkynes: Regioselective Synthesis of Functionalized Ketones via C≡C Triple Bond Cleavage
Direct oxidative coupling of phenols and terminal alkynes was achieved at room temperature by a visible-light-mediated copper-catalyzed photoredox process. This method allows regioselective synthesis of hydroxyl-functionalized aryl and alkyl ketones from simple phenols and phenylacetylene via C≡C triple bond cleavage. 47 examples were presented. From a synthetic perspective, this protocol offers an
Pyrazoline derivatives useful as insecticides having the formula ##STR1## wherein R.sup.1 represents hydrogen atom, a lower alkyl group, (CH.sub.2).sub.n CN group, (CH.sub.2).sub.n OR group, phenyl group or a halogen-substituted phenyl group; R.sup.2 represents hydrogen atom or methyl group; Y represents hydrogen atom or chlorine atom; X represents oxygen atom, sulfur atom, sulfinyl or sulfonyl group; R.sup.3 represents a halogen-substituted lower alkyl group; and n is integer 1 to 3 and R represents a lower alkyl group.