Zhuang Q.-B,
Tian J.-R,
Lu K,
Zhang X.-M,
*,
Zhang F.-M,
Tu Y.-Q,
*,
Fan R,
Li Z.-H,
Zhang Y.-D.
Lanzhou University and Shanghai Jiao Tong University, P. R. of China
Catalytic Asymmetric Polycyclization of Tertiary Enamides with Silyl Enol Ethers:
Total Synthesis of (–)-Cephalocyclidin A.
J. Am. Chem. Soc. 2023;
145: 26550-26556
DOI:
10.1021/jacs.3c11178
Key words
(–)-cephalocyclidin A - asymmetric cyclization cascade - Wilkinson decarbonylation
- Fleming–Tamao oxidation - Giese addition
Significance
Zhang, Tu and co-workers report a concise total synthesis of (–)-cephalocyclidin A.
Key to their approach is a Cu(II)-catalyzed enantioselective polycyclization cascade
of tertiary enamides with terminal silyl enol ethers. The development and scope of
this methodology is also reported in the highlighted paper.
Comment
Enamide E undergoes an intramolecular cyclization cascade to give H via nucleophilic attack of the enamine onto the carbonyl and subsequent trapping
of the generated iminium with the enol ether. A second salient feature is the Giese
addition, from K to L, furnishing the last carbocycle in the caged natural product.
