Application of the aza-Diels-Alder reaction in the synthesis of natural products.
The Diels-Alder reaction that involves a nitrogen atom in the diene or dienophile is termed the aza-Diels-Alder reaction. As well as the powerful all-carbon Diels-Alder reaction, the aza-Diels-Alder reaction has also played an important role in the total synthesis of natural products. Herein, we review various natural products using an aza-Diels-Alder reaction as a key step to their total synthesis, and divide the syntheses into inter- and intra-molecular aza-Diels-Alder reactions and a retro-aza-Diels-Alder reaction. Inter- and intra-molecular aza-Diels-Alder reactions involve an imine as an electron deficient dienophile and an imine as an electron deficient azadiene. The significance of the aza-Diels-Alder reaction for the construction of a six-membered ring containing nitrogen is tremendous, but the development of asymmetric, in particular catalytic enantioselective intramolecular aza-Diels-Alder reaction in the total synthesis of natural products remains highly challenging, and will no doubt see enormous advances in the future.
College of Science, Huazhong Agricultural University, No. 1 Shizishan Street, Hongshan District, Wuhan, 430070, China. xusz@mail.hzau.edu.cn.
Min-Hui
MH
Cao
Nicholas J
NJ
Green
Sheng-Zhen
SZ
Xu
D001688:Biological Products / Q000138:chemical synthesis* / Q000737:chemistry; D060326:Chemistry Techniques, Synthetic / Q000379:methods*; D007097:Imines / Q000737:chemistry
D001688:Biological Products; D007097:Imines