6,6-二烷基富烯与有机锂的反应——双(取代环戊二烯基)钛、锆衍生物的合成

Reaction of 6,6-dialkylfulvene with organolithium——Syntheses of substituted titanocene and zirconocene derivatives

本文研究了6,6-二烷基富烯与有机锂反应的立体效应。6,6-二甲基、甲基乙基、二乙基、甲基苯基富烯与乙基锂易发生环外双键的还原反应。6-甲基-6-正丙基、异丁基富烯同正丁基锂则发生环外双键的加成反应。6,6-多亚甲基富烯[C_5H-4=C(CH_2)_n]与有机锂的反应随n值不同而异,n=4的富烯同正丙基锂和正丁基锂进行α-攫氢和环外双键还原的竞争反应;n=5,6的富烯与乙基锂、异丙基锂和异丁基锂发生还原反应,与正丙基锂和正丁基锂则进行加成与还原的竞争反应。n=4的富烯与芳基锂发生α-攫氢反应,随n值增大则倾向于加成反应。通过上述反应所得的锂化合物合成了一系列新的仲、叔烷基和烯基取代的环戊二烯基钛、锆衍生物。应用~1H NMR证明了化合物的结构。

The steric effects on the reaction of 6, 6-dialkylfulvene with organolithium have been studied. Reaction of ethyllithium with 6, 6-dialkylfulvene, CH=CHCH=CHC= CRR^1, when R=CH_3R^1=CH_3, C_2H_5, C_6H_5; R=R^1=C_2H_5, readily results in the formation of reduetion products. The addition produets were formed by the reaction of n-butyllithium with 6, 6-dialkylfulvene when R=CH_3, R^1=n-C_3H_7, n-C_4H_9. The analogous reaction of 6, 6-polymethylenefulvene, CH=CHCH=CHC=C(CH_2)_n with organolithium (R^2 Li) was also examined and found that when n=4, R^2=n-C_3H_7, n-C_4H_9, both α-hydrogen elimination and reduction products were formed, and when n=5 or 6, R^2=C_2H_5, i-C_3H_7, i-C_4H_9, only the reduction products was formed, but when R^2=n-C_3H_7, n-C_4H_9, both addition and reduction reactions took place simultaneously. Reaction of tetramethylenefulvene with aryllithium only leads to α-hydrogen, elimination and in the case of penta- and hexamethylenefulvene addition reaction takes place. Besided, a series of sec- and tert-alkyl and cycloalkenyl substituted titanocene and zirconocene derivatives have been prepared and their ~1H NMR spectra was discussed.