Study On The Cross-coupling Reaction Of Oxidized C(sp~3)-H/PH Catalyzed By Silver Or Iron

Organophosphorus compounds containing C(sp~3)-P bonds usually have a wide range of physiological activities,special chemical reactivities and excellent photoelectric properties,which are widely used as medicines,pesticides,chemical fertilizers,industrial extractants,chemical weapons,ligands and organic functional materials.At present,the construction of carbon-phosphorus bonds mainly depends on the traditional reactions between phosphites and their derivatives with halogenated alkanes.However,these reactions have many problems,such as poor generality of the substrates,difficult to obtain substrates,and difficult to control the reaction conditions.In recent years,transition-metal involved oxidative dehydrogenation cross-coupling refers to the cleavage and recombination of C-H bonds to form new carbon-carbon bonds or carbon-hetero bonds,thus avoiding the preactivation of substrates and overcoming the disadvantages of the conventional reactions.These newly developed strategies have high atomic economy,and live up to the idea of green chemistry.Therefore,transition metal-catalyzed oxidative dehydrogenation cross-coupling reaction is the most ideal route for the synthesis of organophosphorus compounds containing C(sp~3)-P bonds at present.In this paper,we have developed two types of transition-metal catalyzed oxidative cross-coupling reactions of organophosphorus reagents with simple non-activated substrates.The first part is silver-catalyzed C(sp~3)-P bond formation through oxidative dehydrogenation cross-coupling of dialkylphosphonates with simple ketones,thus producing the ?-ketophosphonates by one step synthesis.We conducted comprehensive screening of the reaction conditions and explored the applicability of the substrates.For mechanism studies,we conducted the corresponding control experiments and deuterium experiments,which fully demonstrated that the reaction went through a free radical process,finally we proposed the possible reaction mechanism.In the second part of this artical,we preliminarily explored the cross-coupling reaction of iron-catalyzed ether compounds with diarylphosphine oxide compounds.We screened the reaction conditions,explored the reactivity of several substrates,and proposed the possible mechanism of the reaction.However,the yields of the reaction are not satisfying,and subsequent experiments will be further carried out.