Construction Of Benzo Aza-polycyclic Skeleton

The thesis focuses on the construction of the fused aza-polycyclic skeleton through the intramolecular Schmidt reaction of acyl chlorides with alkyl azides. The key innovation of the research is to control the migration group of the Schmidt reaction of acyl chlorides, and the N-acyliminium ions is addressed through1,2-migration of a methine group over the methylene group with the designed ω-azido carboxylic acids. The intramolecular capture of the N-acyliminium ions with aromatic rings is documented, which avoids the loss of carbon atom and enhances the atom efficiency of the related conversion. The dissertation is composed by the following three parts:In the first part, the classic Schmidt reaction of carboxylic acids with hydrazoic acid has been reviewed. Generally, the products are one-carbon shorter homologs of the substrates. The possible mechanism and the process of the conversion are introduced here.In the second part, the Schmidt reaction of acyl chlorides is presented. The Schmidt reaction of acyl chlorides with alkyl azides through N-acyliminium ion intermediates has been designed and realized. Several ω-azido carboxylic acids have been converted to the corresponding benzo fused lactams through the one-pot protocol combining acyl chlorination, Schmidt reaction, and Pictet-Spengler cyclization. The important feature of the domino process is the efficiency in bond reorganization (three new bonds including one C-C and two C-N bonds formed, meanwhile one C-C bond broken) and ring formation (bicyclic skeleton constructed).In the last part, the experimental details of the conversion and spectroscopy data are provided, which includes the preparation of all the intermediates, the ω-azido carboxylic acids, and the one-pot conversion combining with acyl chlorination, Schmidt reaction, and Pictet-Spengler cyclization.