| Autor: |
Cai W; Institute of Chemistry & BioMedical Sciences , Nanjing University , Nanjing 210023 , China., Wu J; Institute of Chemistry & BioMedical Sciences , Nanjing University , Nanjing 210023 , China., Zhang H; Institute of Chemistry & BioMedical Sciences , Nanjing University , Nanjing 210023 , China., Jalani HB; Institute of Chemistry & BioMedical Sciences , Nanjing University , Nanjing 210023 , China.; Smart BioPharm , 310-Pilotplant, Incheon Techno-Park, 12-Gaetbeol-ro , Yeonsu-gu, Incheon 21999 , South Korea.; College of Pharmacy , Yonsei University , 85-Songdogwahak-ro , Incheon 21983 , South Korea., Li G; Institute of Chemistry & BioMedical Sciences , Nanjing University , Nanjing 210023 , China.; Department of Chemistry and Biochemistry , Texas Tech University , Lubbock , Texas 79409-1061 , United States., Lu H; Institute of Chemistry & BioMedical Sciences , Nanjing University , Nanjing 210023 , China. |
| Abstrakt: |
An efficient synthesis of 4-methyleneproline derivatives has been developed through an Rh-catalyzed [4 + 1] cycloaddition strategy using 3-methyleneazetidines and diazo compounds. The reaction proceeds under very mild conditions with a high degree of chemoselectivity, and competing experiments revealed that it is the preferred reaction, dominant over the C-H insertion, O-H insertion, and olefin cyclopropanation reactions which are commonly observed in Rh carbene chemistry. This method can incorporate the proline ester scaffold in pharmaceuticals and natural products. The intramolecular version of the reaction effectively provides proline-fused small to medium-sized tricyclic heterocycles. Gram-scale reactions, one-time addition of diazo compounds, and a minimum catalyst loading of 0.1 mol %, proceeded smoothly, implying their practicality. |
