Study On Formylation And Acylation Of Aryl Compounds As Well As Construction Of The Key Skeleton Structure Of Communesin F

Aromatic aldehydes and aryl ketones are important compounds in organic chemistry,which are widely used in pharmaceuticals,pesticides,natural products and other fields.They are also one of the most valuable synthetic intermediates with versatile transformations in C-C and C-N bond-forming reactions.The communesins alkaloids are a family of complex polycyclic natural products isolated from various terrestrial and marine Penicillium fungi which have been shown to possess significant cytotoxicity and insecticidal activity.Our interest is mainly targeted in studying the formylation and acylation of aryl compounds as well as construction of the key skeleton structure of communesin F.This dissertation contain the following three sections.In the first part,the recent progress of preparation of aromatic aldehyde and application of aromatic aldehyde in organic synthesis has been reviewed.A formylation of aryl iodides under room temperature by using weaker base KOMe instead of t Bu Li was developed.The TMS-TMS disilane was discovered to play crucial roles in this formylation.It was discovered that the Me O^-group of KOMe coordinated with two silyl groups of disilane to generate a hypercoordinate silane species through ¹³C and²⁹Si NMR experiments.This hypercoordinate silane species reacted with aryl iodide to give aryl carbanion,which underwent formylation with DMF to give the aryl aldehyde.In the second part,the application of aromatic ketones,especially acylation reactions of aromatics using aldehydes as acyl surrogates by ortho C–H activation has been reviewed detailedly.A novel direct C-H acylation of phenylpyridine has been developed by merging photocatalyzed Hydrogen Atom Transfer with palladium catalysis.In this method,the excited state of phenanthrenequinone under blue light irradiation and aldehydic C-H-bond can initiate aldehyde free radicals through the hydrogen atom transfer（HAT）process,and then aromatic,heteroaromatic and aliphatic ketones were formed by oxidation and reductive elimination process.In the third part,we have attempted to construct the critical skeleton of communesin F based on three catalytic systems of Mac Millan group and developed strategy by our research group about visible light-excited cyclization of tryptamines.The 3-76 and 3-77 were synthesized by our method to verify the initiation process of radical.constructing the C-N bond under photoredox conditions realize the analogue communesin F aminal structure skeleton,which layed a solid foundation for the subsequent total synthesis of this natural product.