Rhodium-Catalyzed Oxidative Cyclizations Of Isoquinolones With α-Diazo Carbonyl Compounds

In this thesis,we have successfully established efficient methodologies for the synthesis of isoindolo[2,1-b]isoquinoline-7-carboxylate and three kinds of novel isoquinolone-containing spiro compounds through rhodium-catalyzed oxidative cyclizations of NH-isoquinolone derivatives with α-diazo carbonyl compounds.The main results are as follows:Firstly,a novel and practical procedure for the preparation of isoindolo[2,1-b]isoquinoline-7-carboxylate derivatives through a Rh(III)-catalyzed oxidative [4+1] cycloaddition of isoquinolones with diazoketoesters followed by an in situ deacylation reaction is developed.More intriguingly,the title compounds could be easily converted into isoindolo[2,1-b]isoquinolin-5(7H)-ones via de-esterification,which are rosettacin analogues and frequently found in various natural alkaloids and synthetic drug molecules.Secondly,a Rh(Ⅲ)-catalyzed site-selective oxidative spirocyclization reaction of NH isoquinolones with α-diazo-1,3-indandiones leading to the formation of three kinds of novel spiro compounds via double C-H and N-H/C-H cleavage has been realized.Notably,the regioselectivity of this transformation can be easily controlled by employing appropriate NH isoquinolone substrates or tuning the reaction parameters.In addition,a plausible catalytic cycle is proposed based on control experimental results.Finally,we also investigated the further transformations of the above spiro-products.