The 2,7-dilithiated substrates of 3,6-dimethylthieno[3,2-b]thiophene, N,N′-dimethylpyrrolo[3,2- b]pyrrole and N-methylthieno[3,2-b]pyrrole were reacted with W(CO)6 to give, after subsequent alkylation with Et3OBF4, the ditungsten biscarbene complexes [(CO)5WC(OEt)XXC(OEt)} W(CO)5] (XX = condensed heteroaromatic spacers). Sites of attack during the dilithiation of the condensed rings were studied and compared, and the yields of the desired ditungsten biscarbene complexes optimized by changing the reaction conditions according to the role of the heteroatoms in the rings. The crystallographic data of the three ditungsten biscarbene complexes are reported and their structural features compared. The methyl substituents on the condensed heteroaromatic rings play an important role in determining the molecular configurations.
3,6-二甲基噻吩并[3,2-b]噻吩、N,N′-二甲基
吡咯并[3,2-b]
吡咯和N-甲基
噻吩并[3,2-b]
吡咯的2,7-二
锂基底物与W(CO)
6反应,经过随后的乙基化反应与Et
3OBF
4,得到二
钨双卡宾配合物[(CO)
5WC(OEt)XXC(OEt)} W(CO)
5](XX = 紧凑的杂
芳烃间隔)。研究和比较了在对紧凑环进行二
锂化时的攻击位点,并通过根据环中杂原子的作用改变反应条件来优化所需的二
钨双卡宾配合物的产率。报告了三种二
钨双卡宾配合物的晶体学数据,并比较了它们的结构特征。紧凑杂
芳烃环上的甲基取代基在确定分子构型方面起着重要作用。