Microwave-Assisted Tandem Reactions For Building Isoindolin-1-one And Isoquinolin-1-one Scaffolds

In organic chemistry there are many name reactions. Wittig reaction and Diels-Alder reaction are very important reactions in organic synthesis. Wittig reaction is a valuable method to form the carbon-carbon double bond, which is widely used in total synthesis of natural products and organic intermediates. In addition, the intramolecular Diels-Alder reaction can generates carbon-carbon bonds to produce a polycyclic compound. It can also form stereo-centers in a single step. It has many merits, such mild reaction conditions, high yields, good stereoselectivity and predictability. There are many reports about the microwave assisted Diels-Alder reaction. For many advantages of microwave assisted reactions, and the wide application of Wittig and Diels-Alder reaction in organic synthesis, we investigated microwave assisted 'one pot' Wittig-intramolecular Diels-Alder reaction for synthesis bicyclic lactams:Hexahydro-1H-isoindolone and Hexahydro-2H-isoquinol-inone.In chapter 1, there is a review about the structure of bicyclic lactams and their existence in natural products or bioactive molecules, which also contains corresponding methods to synthesize them. In addition, we talk about the investigation of microwave assisted organic reaction, the Wittig reaction, the intramolecular Diels-Alder reaction contained the mechanism and the stereochemistry of Dials-Alder reaction, and microwave assisted intramolucular Diels-Alder reaction. In chapter 2, there is a discussion about 'one pot' system of Wittig-intramolecular Diels-Alder reaction which is utilized in synthesis of 6/5-lactams and 6/6-lactams. Then an illustration about the preparation of materials is described in detail. After a modification of Wittig-intramolecular Diels-Alder reaction,α-bromoacetamide, PPh3, aldehyde and alkali were mixed in aqueous THF and converted to aimed products under the assistance of microwave heating. The results of reactions show that almost E-olefins are built at the step of Wittig reaction, yet no better choice in stereochemistry after Diels-Alder reaction, which is detected by 1H NMR spectrum. The stereochemistry of products is finally detected by correlative literatures and X-Ray.The experimental section compiles the main synthetic procedures, the characterization data for the key compounds, and the cited references. Copies of the original 1H and C NMR spectra and the X-ray single crystal structural analysis data are found in the Appendix.