Cobalt-catalyzed Oxidative Alkylation Of Styrenes And Benzoylation Of Amines

Transition metal catalysts are widely used in organic synthesis,but there are still some shortcomings in some reactions,such as high price,low activity,harsh reaction conditions.Compared with other transition metal catalysts,the unique catalytic effect of cobalt catalyst has attracted many researchers' attention.Palladium,rhodium,copper and other precious transition metal catalysts are mostly used in oxidative alkylation of alkenes and amidation between amines and aryl peroxides.With the development of organic chemistry in the concern of environmental issues,the transition metal cobalt catalyzed reation has become a hot spot in green organic chemistry.In this paper,the coblat-catalyzed oxidative alkylation of olefins and ethers and benzoylation of amines and aryl peroxides are investigated.1.It is the oxidation alkylation of styrene throughthe ?-C(sp~3)-H bond activation of ether under the cobalt catalysis.This reactionwas proceeded with styrene andtetrahydrofuran as standard substrates,cobalt acetate tetrahydrate(20 mol%)as catalyst,silver carbonateas(2.0 equiv)as oxidant,isobutyl alcohol(10 equiv)as additive at 65 ? for 12 hours.The reaction was carried out under simple and mild conditions,showing good regioselectivity and funtional compatibility.It provided a method to easily prepare ?-oxyalkyl ketones from readily available substrates.2.UUnder the catalysis of cobalt,the benzoylation of amines with arly peroxides was realized.The reaction conditions proceed withamines andbenzoyl peroxide as standard substrates,cobalt acetate tetrahydrate(5 mol%)as catalyst,phenanthroline(10 mol%)as ligant and 1,2-dichloroethane as solvent at 60 ? for 8 hours.The reaction was carried out under mild conditions and no additional oxidant is needed to produce amide products instead of common N-O bond formation products.The reaction is suitable for a series of primary amines and aryl peroxides,showing good range of substrates.The product can still be obtained with 87% yield though large-scale reaction.It provides a novel and simple method for the synthesis of amides.