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

镍催化的偶联反应：双(π-烯丙基)镍和钯的络合物在温和的条件下催化了烷基卤化物和烷基Grignrad试剂之间的交叉偶联反应。在镍催化体系中，通过使用分子中含有两个二元二烯单元的配体，交叉偶联反应被显著地加速，并且二烷基锌试剂可以代替格氏试剂作为偶联伙伴。研究还发现，二氯化镍与乙烯基格氏试剂反应生成含有丁二烯和乙烯基的镍络合物，与环醚反应生成高烯丙基高烯丙基格氏试剂。铜催化偶联反应：铜催化烷基氯在炔类配体存在下的交叉偶联反应。然而，在相似的条件下，仲烷基格氏试剂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烯丙基镁化合物。用不同的亲电剂如烷基溴化物、氯硅烷、烯酮、酸性卤化物或二氧化碳捕获这种形成的化合物，根据亲电剂的结构产生相应的烯烃或烯。钛催化反应：发现茂钛配合物催化苯乙烯与烷基卤化物和烷基格氏试剂的烷基化反应。二氯化钛与乙烯基格氏试剂反应生成二茂钛-二烯络合物，再与另一种乙烯基卤化镁反应生成ATE络合物。在烷基卤化物存在下，通过在丁二烯单元上加成烷基自由基，然后过渡金属反应，形成烷基化的烯丙基Grignrad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.