STERIC EFFECT OF THE REACTION OF 6,6-DIALKYLFULVENES WITH ALKYLLITHIUM AND METAL LITHIUM—SYNTHESIS OF SUBSTITUTED TITANOCENE DERIVATIVES

摘要

＜正＞ The steric hindrance effect of the reaction of 6,6-dialkylfulvenes and 6,6-polymethylene-fulvenes withethyllithium,n-butyllithium,i-butyllithium,cyclopentyllithium,cyclohexyllithium and metal lithium is brief-ly explored by the ~1HNMR of synthetical organotitanium compounds.For the reactions of fulvenes withalkyllithium,the exo-cyclic double bond addition,reduction,and the α-hydrogen abstraction from theside chain of the fulvenes take place.The reduction,reductive coupling and α-hydrogenabstraction reactions occur when metal lithium reacts with fulvenes.The reaction pattern depends on thedifference of the configuration and steric effect of substituents on 6-position of fulvenes andorganolithium.