Synthesis and Catalytic Applications of<i>ansa</i>Compounds with Cycloalkyl Moieties as Bridging Units: A Comparative Study
作者:Alejandro Capapé、Alexander Raith、Eberhardt Herdtweck、Mirza Cokoja、Fritz E. Kühn
DOI:10.1002/adsc.200900708
日期:2010.2.15
(stable up to 180 °C under air, as determined by thermogravimetric studies) and are highly active catalysts at room temperature (molybdenum compounds) or above (tungsten compounds) in olefin epoxidation. In the case of cyclooctene as substrate, TOFs up to ca. 11800 h−1 are obtained. Moreover, most of the catalysts described here display a high selectivity in the epoxidation of cis- and trans-stilbene. In
钼和钨的化合物(莫η 5 -C 5 H ^ 4 [CH(CH 2)Ñ ]-η 1 -CH}(CO)3)和(W η 5 -C 5 H ^ 4 [CH(CH 2)3 ]-η 1 -CH}(CO)3)(图2a,3a中ñ = 3;图2b,图3b ñ = 4;图2c,3c的ñ = 5; 2D,3D ñ = 6)由螺-反应而合成双环化合物1a – d的配合物为[M(CO)3(tach)](M =钼,钨; tach = 1,3,5-三甲基六氢-1,3,5-三嗪)。NMR光谱以及X射线衍射研究证实了分子内ansa桥的形成。该配合物在固态下表现出良好的稳定性(通过热重研究确定,在空气中稳定至180°C),并且在室温(钼化合物)或更高温度下(钨化合物)在烯烃环氧化中是高活性催化剂。在环辛烯作为底物的情况下,TOF最高可达。得到11800h -1。而且,本文所述的大多数催化剂在顺式和-式的环氧化中显示出高选