1. Heterocyclic compounds with oxygen heteroatom (s)only.

2. Heterocyclic compounds with nitrogen heteroatom(s)only.

3. However, the resolution in the dimension of the heteroatom of indirect detection experiments can not meet the requirement of resonance assignment.

4. The key step was a substrate controlled asymmetric heteroatom conjugated addition.

5. The results showed that the aromatic ratio, heteroatom and metal contents contribute to the high polarity of the asphaltenes. This is the basis of other properties of heavy oil.