Development of Synthetic Reactions Catalyzed by Transition Metal Complexes Having π-Electron Accepting Carbon Ligands

镍催化偶联反应：研究表明，双(π-烯丙基)镍和钯配合物在温和条件下催化卤代烷与烷基格氏试剂之间的交叉偶联反应。通过在镍催化体系中使用分子中具有两个图二烯单元的配体，发现交叉偶联反应显着加速，并且可以使用二烷基锌试剂代替格氏试剂作为偶联配偶体。还发现二氯化镍与乙烯基格氏试剂反应生成具有丁二烯和乙烯基的镍配合物，该配合物与环醚反应得到烷基化高烯丙基格氏试剂，收率良好。 Cu催化的偶联反应：Cu在炔配体存在下催化烷基氯的交叉偶联反应。然而，在相似的条件下，仲烷基和叔烷基格氏试剂与二烯或烯炔反应，通过碳镁化得到烷基化烯丙基镁化合物。用各种亲电子试剂例如烷基溴、氯硅烷、烯酮、酰基卤或二氧化碳捕获由此形成的化合物，根据亲电子试剂的结构得到相应的烯烃或丙二烯。 Ti催化反应：发现二茂钛络合物可以催化苯乙烯与烷基卤和烷基格氏试剂的烷基化反应。二氯化二茂钛与乙烯基格氏试剂反应形成二茂钛-二烯络合物，然后与另一种乙烯基卤化镁反应形成醋酸络合物。在烷基卤化物存在下，通过将烷基加成到丁二烯单元上，然后进行金属转移，形成烷基化烯丙基格氏试剂。

Ni-catalyzed coupling reactions:It has been revealed that bis (π-allyl) nickel and palladium complexes catalyze cross-coupling reaction between alkyl halides and alkyl Grignrad reagents under mild conditions. By the use of ligands that have two tutadiene units in the molecule in Ni-catalyzed systems, cross-coupling reaction was found to be dramatically accelerated and dialkyl zinc reagents can be used as the coupling partners instead of Grignard reagents. It was also found that nickel dichloride reacts with vinyl Grignard reagents to form nicklate comples possessing butadiene and vinyl group which reacted with cyclic ethers to give alkylated homoallyl Grignard reagents in good yields.Cu-catalyzed coupling reactions: Cu catalyzes cross coupling reaction of alkyl chlorides in the presence of alkyne ligands. Under similar conditions, however, secondary and tertiary alkyl Grignard reagents reacted with dienes or enynes to give alkylated allylmagnesium compounds via carbomagnesation. Trapping of thus formed compounds with various electrophiles such as alkyl bromides, chlorosilanes, enones, acid halides, or carbon dioxides, afforded corresponding olefins or allenes depending on the structures of electrophiles. Ti-catalyzed reaction: titanocene complex was found to catalyze alkylation of styrenes with alkyl halides and alkyl Grignard reagents. Titanocene dichloride reacted with vinyl Grignrad reagents to form a titanocene-diene complex which then react with another vinylmagnesium halides to form an ate complex. In the presence of alkyl halides, alkylated allyl Grignrad reagents were formed via addition of alkyl radical to the butadiene units followed by transmetallation.