Reductive Cyclization of Nitro and Azide Compounds with Aldehydes and Ketones Promoted by Metallic Samarium and Catalytic Amount of Iodine

摘要

Since pioneering studies by Kagan and his group demonstrated the particular effectiveness of samarium diiodide (SmI_2) as a mild, neutral, ether-soluble, one-electron transfer reducing agent, the utilization of SmI_2 in synthetic organic chemistry has been extensively documented. However, problems can arise when SmI_2 is used as a reductant. SmI_2 invariably cannot meet he demand of atom economy. On the other hand, metallic samarium is stable in air, and its strong reducing power (Sm~(3+)/Sm = -2.41 V) is similar to that of magnesium (Mg~(2+)/Mg = 02.37 V). It has been noted recently that metallic samarium can be used directly in organic synthesis. As a result, we wish to use the more convenient and cheaper samarium, instead of SmI_2, directly as a reluctant.