Photoinduced Lanthanum Catalysis: C-H Activation and Spirocyclization
Zhenhong Gan1, Xiaoyan Cai2, Liming Chen2
1Key Laboratory of Modern Analytical Science and Separation Technology of Fujian Province, School of Chemistry, Chemical Engineering, and Environment, Minnan Normal University, Zhangzhou 363000, China.
Organic Letters
|December 9, 2025
Summary
Lanthanum bromide catalyzes a novel tandem reaction for C-H oxidation and spirocyclization using molecular oxygen. This efficient method precisely functionalizes complex molecules, yielding diverse spirocyclic compounds under ambient conditions.
Area of Science:
- Organometallic Chemistry
- Catalysis
- Organic Synthesis
Background:
- Developing efficient methods for complex molecule synthesis is crucial.
- Spirocyclic compounds are important structural motifs in pharmaceuticals.
- C-H functionalization offers a powerful route to molecular complexity.
Purpose of the Study:
- To report a novel lanthanum-catalyzed tandem reaction.
- To achieve C(sp3)-H oxidation and spirocyclization under ambient conditions.
- To explore the mechanism of this transformation.
Main Methods:
- Lanthanum-catalyzed tandem reaction.
- Utilizing molecular oxygen as the oxidant.
- In situ multicomponent coordination for catalyst assembly.
- Mechanistic studies involving energy and electron transfer pathways.
Main Results:
- Efficient synthesis of N,O- and O,O-spirocyclic compounds.
- Broad functional group tolerance demonstrated.
- Precise functionalization of complex scaffolds achieved.
- Lanthanum bromide acts as both photosensitizer and Lewis acid catalyst.
Conclusions:
- A new, ambient-condition method for spirocyclization is established.
- The reaction proceeds via synergistic energy and electron transfer.
- Lanthanum bromide plays a dual catalytic role, enabling C-H cleavage and cyclization.
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