Starke metallorganische Lewis-Säuren, III [1] Reaktionen von Tricarbonyl-η5-cyclopentadienylmolybdäntetrafluoroborat mit cyclischen Ethern (CH2)nO (n = 2,3,4) und Dioxan / Strong Organometallic Lewis Acids, III [1] Reactions of Tricarbonyl-η5-cyclopentadienyl Molybdenum Tetrafluoroborate with Cyclic Ethers (CH2)nO (n = 2, 3, 4) and Dioxane

Abstract

Abstract Tetrafluoroborate in (η5-C5H5)(OC)3MoFBF3 is easily substituted by cyclic ethers (CH2)nO (n = 2,3,4)at -30°C in CH2Cl2 to give cationic complexes[(η5-C5H5)(OC)3MoO(CH2)n]+BF4-. With dioxane mononuclear and dinuclear dioxane bridged cationic complexes have been obtained. Ring opening of oxirane in [(η5-C5H5)(OC)3MoO(CH2)2]+ occurs at low tem-peratures; in the presence of oxirane or acetone formation of dioxane or 2,2-dimethyl-1,3-dioxolane, respectively, has been observed. The dioxolane has been obtained also in high yield by direct cyclisation of oxirane and acetone using [(η5-C5H5)(OC)3Mo(acetone)]+ as catalyst.