Catalytic Cyclopropanation with Iron(II) Complexes

摘要: Iron(II) complexes of meso-tetra-p-tolylporphyrin (TTP), tetramethyldibenzotetraaza[14]annulene (tmtaa), and trans-1,2-bis(salicylidene)cyclohexanediamine (saldach) catalyzed the cyclopropanation styrene with aryldiazomethanes. When p-tolyldiazomethane was used as carbene source, trans-cyclopropanes were major products. Trans/cis ratios up to 17:1 obtained. However, using mesityldiazomethane resulted in a reversal stereoselectivity, giving cis-cyclopropanes product (cis/trans 2.9:1). The stereoselectivity iron(II) porphyrin-catalyzed reactions enhanced by performing at low temperature or bulky porphyrin ligands. Using trimethylsilyldiazomethane trimethylsilylcyclopropanes produced excellent yields (TTP)Fe. On treatment (TTP)Fe diazoreagents, observed spectroscopically. These transferred their ligand produce cycl...