摘要：

Versatile carbon-carbon bond-forming reactions using lanthanide triflates (Ln(OTf) 3 ) as catalysts are discussed. Lanthanide triflates are new types of Lewis acids different from typical Lewis acids such as AlCl 3 , BF 3 , SnCl 4 , etc. While most Lewis acids are decomposed or deactivated in the presence of water, lanthanide triflates are stable and works as Lewis acids in water solutions. Many nitrogen-containing compounds such as imines and hydrazones are also successfully activated by using a small amount of Ln(OTf) 3 . Lanthanide triflates are also excellent Lewis acid catalysts in organic solvents. A catalytic amount of Ln(OTf) 3 is enough to complete reactions in most cases. In addition, Ln(OTf) 3 can be recovered after reactions are completed and can be reused. Several chiral lanthanide catalysts for asymmetric Diels-Alder, aza Diels-Alder, and 1,3-dipolar cycloaddition reactions are also described.

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