Transition-metal-catalyzed C-H Activation And Functionalization For Synthesis Of Phthalazinone Derivatives

In this paper,transition-metal-catalyzed C-H bond activation and alknylation,amination,acylation of 4-Arylphthalazin-1（2H）-ones were studied,and a series of related derivatives were synthesized.Therefore,the resulted 4-arylphthalazin-1（2H）-one derivatives will be of great value for their application in pharmaceutical chemistry.This paper consists of three parts:（1）Rhodium catalyzed C-H activation alkynylation of 4-arylphthalazin-1（2H）-oneFirst of all,we used 4-arylphthalazin-1（2H）-one and tips bromoacetylene as substrates,with[Cp*Rh Cl₂]₂ as the catalyst,silver carbonate as the salt,and DCE as the solvent.Mono-alkynylation products with high yields were obtained by 100°C oil bath reaction for 12 h;When silver carbonate and silver hexafluoroantimonate were used as mixed salts,dialkynylation products with high yield were obtained by 100°C oil bath reaction in DCE solvent for 12 h.Different salts can make different effect on alkynylation reaction.In addtion,triethyl（TES）bromoacetylene is also a good coupling partner,which can complete the C-H Alkynylation.Signifficantly,silver salt Ag Sb F₆ plays an important role in promoting dialkynylation,4-arylphthalazin-1（2H）-one can be selectively monoalkynylation and dialkynylation,respectively.（2）Iridium catalyzed C-H activation amination of 4-arylphthalazin-1（2H）-oneNext,we used 4-Arylphthalazin-1（2H）-one and p-toluenesulfonyl azide（Ts N₃）as as substrates.Under the catalysis of[Ir Cp*Cl₂]₂ and silver bis（trifluoromethane）sulfonimide,the reaction was carried out in 100°C oil bath in DCE for 12 h.The mono-amination products were obtained;moreover,with excess p-toluenesulfonyl azide（Ts N₃）,diamination products with high yield were obtained by 100°C oil bath reaction in DCE for 12 h.（3）Palladium catalyzed C-H activation acylation of 4-arylphthalazin-1（2H）-oneFinally,the acylation of 4-Arylphthalazin-1（2H）-one with benzoic acid was carried out in the presence of Pd（OAc）₂,silver carbonate and ammonium persulfate.A serious of 4-arylphthalazin-1（2H）-one with a acyl group were synthesized in high yield in 100°C oil bath for 18 h.