Synthesis And Application Of Cyclopalladated Ferrocenylimine Containing Ester Group For Heck And Suzuki Coupling Reactions

In this thesis, four cyclopalladated ferrocenylimine catalysts containing ester group were synthesized and their catalystic propertiese for Heck coupling reaction and Suzuki coupling reaction were investigated.1. The cyclopalladated ferrocenylimine catalysts containing ester group (Scheme1) were prepared and characterized by’H NMR,13C NMR, IR and MS. These cyclopalladated complexes were thermally stable and insensitive to oxygen and moisture. Whether you used which one of the la,1b,2a and2b, could get the similar yield. Here, we took la as an example. Scheme1Synthesis of cyclopalladated ferrocenylimine2. The application of catalyst la in the Heck coupling reaction in organic phase was studied (Scheme2). First of all, compared with the conventional catalysts, the amount of0.1mol%1a used in experiement was lower, which showed that it had high catalytic avtivity. Secondly, for a variety of substituted bromobenzene, when the substituent was electron-withdrawing groups, regardless of substituents in what position, a high yield could be obtained. Simultaneously, this catalytic system was also applicable to heterocyclic aromatics, which showed a wide substrate range for this catalyst system. Scheme2Heck coupling reaction catalyzed by la3. In the presence of0.1mol%compound la, Suzuki reaction in aqueous phase in moderate to give good yields (Scheme3). Inactive aryl halides with electron-don-ating groups gave rise to symmetrical biaryls in lower yields;P-substituted substrates offered slightly higher yields than that in o-substituents substrates. However, in the case of aryl halides with electron-withdrawing groups, high yields could be obtained either o-or m-substituted substrates, only lower to the substrates of P-substituted. A higher yield for Heterocyclic aromatics also could be obtained. The advantages of this catalyst system were that small amount of catalyst was used and pure water as solvent compared to traditional organic solvent, which was an important part of green chemistry using a friendly reaction medium. Scheme3Heck coupling reaction catalyzed by la4. We examined the catalytic efficiencies of complex la in Suzuki coupling reaction in organic phase. The results showed that, substrate was not sensitive to the electronic effect, regardless of the substituents were electron-donating or electron withdrawing groups, a high yield could be obtained. Substrate was more sensitive to the spatial effect, the yield was higher for the substrates with substituent group on the P-position due to the small steric hindrance. This reaction could be finished within two hours. Scheme4Suzuki coupling reaction catalyzed by1a5. We studied1a in the Suzuki coupling reaction in water (Scheme5). The results obtained showed that1a had good catalytic effect when the solvent used as water. Scheme5Suzuki coupling reaction catalyzed by1a...