Research On Palladium-and Cobalt-Catalyzed New C-C Bonds Forming Reaction

Efficient construction of C-C bonds played a key role in organic synthesis. Transition metal-catalyzed C-C bonds formation reaction paved the way for atom economic green chemistry. Development of new palladium or cobalt catalyzed elementary reaction provided a way to construct new organic molecules, shorten synthesis routes, and lower the cost, and then meet the demands of atom economic green chemistry. Research process in allyl palladium chemistry, palladium catalyzed [3+2] cycloaddition, and transition metal catalyzed functionalization of C6o were reviewed in this doctoral dissertation and research results going around these three research fields were shown below.In presence of Pd2(dba)3.CHCl3and BINAP, the reaction of cyanoacetic acid allyl ester with activated olefins7underwent smoothly to afford acetonitrile-allylation products11in35%-83%yields. Mechanism research showed that this reaction probably underwent through acetonitrile-allyl-palladium intermediate P’. In presence of Pd(PPri3)4, reaction between cyanoacetic acid allyl ester and C60underwent smoothly to afford corresponding acetonitrile-allylation products12in31%yield, and40%C6o was recovered.In the presence of Pd9(dba)3.CHCl3and PPh3, the reaction of propargyl trifluoroacetates13, activated olefins7and allyltributylstannane underwent smoothly to afford [3+2] cycloaddition products in31%-87%yields. This new palladium catalyzed [3+2] cycloaddition reaction provided a new synthesis method for multi-substituted and high functionalized carbocyclic five-membered rings.A new cobalt catalyzed selective hydroalkylation reaction of C6o was developed. In presence of CoCl2dppe, Mn and H2O, hydroalkylation reaction between activated bromoalkanes and C60underwent smoothly. Chemical yield was improved to76%after optimization of reation conditions. All kinds of activated bromoalkanes, including benzyl bromides15a-f, allyl bromides15g-h and propargyl bromides15i-j, could attend this reaction. This reaction was also successfully applied to synthesis of ZnP-C60161, fullerene-bound dendrimer16m and fullerene dimer16n, and the isolated yields are30%,48%and39%respectively. In presence of stoichiometric amount of KO’Bu, hydroalkylated products underwent dimerization smoothly to afford corresponding singly bonded C60dimers17a-f in31-71%yields.