C-Arylation reactions catalyzed by CuO-nanoparticles under ligand free conditions

• Mazaahir Kidwai,
• Saurav Bhardwaj and
• Roona Poddar

Beilstein J. Org. Chem. 2010, 6, No. 35, doi:10.3762/bjoc.6.35

• of attention has been focused on the development of Pd catalyzed arylation [8][9][10][11]. Another important protocol involves arylation of activated methylene compounds mediated by copper salts [12][13]. Recently, proline has also been used along with CuI for C-arylation [14]. But some of the

• methods suffer from serious drawbacks and limitations, for example, long reaction times [15][16], the high cost of Pd catalysts [17][18] and the need for stoichiometric amounts of copper salts. In addition to these problems, the major drawback is that the majority of catalysts cannot be reused [19]. To

• copper salts such as Cu(OAc)2 and ordinary CuO were found to be inferior to CuO-nanoparticles and gave low yields of 3-phenylpentane-2,4-dione. Moreover, Cu-nanoparticles which have been used for O-arylation and S-arylation [34][35], were not effective in the coupling reaction (Table 1). In addition

Synthesis and Diels–Alder cycloaddition reaction of norbornadiene and benzonorbornadiene dimers

• Bilal Nişancı,
• Erdin Dalkılıç,
• Murat Güney and
• Arif Daştan

Beilstein J. Org. Chem. 2009, 5, No. 39, doi:10.3762/bjoc.5.39

• -bromobenzonorbornadiene 4 was treated with n-BuLi at −78 °C and the resulting anion was quenched with trimethyltin chloride, a single trimethyltin derivative 6 was observed in the crude reaction mixture and was finally isolated in 91% yield. Copper salts have been successfully employed for Stille-type hetero-coupling

N-Arylation of amines, amides, imides and sulfonamides with arylboroxines catalyzed by simple copper salt/EtOH system

• Zhang-Guo Zheng,
• Jun Wen,
• Na Wang,
• Bo Wu and
• Xiao-Qi Yu

Beilstein J. Org. Chem. 2008, 4, No. 40, doi:10.3762/bjoc.4.40

• -containing substrates with arylboroxine conducted in protic solvent only with the use of copper salts has not been explored previously. Results and Discussion Firstly, we chose phthalimide and phenylboroxine as model substrates to optimize the catalytic conditions (copper source, temperature, solvent, amount

• of catalyst) to achieve the best results in the cross-coupling reactions (Scheme 2). Several simple copper salts were tested as copper sources to promote the coupling reaction with methanol as solvent. As shown in Table 1, most copper salts (20 mol %) that were used gave the desired products in high

• yields (Table 1, entries 1–10), and the counterion did not play a significant role. This result is much better than previously reported [10] for a similar catalytic system. However, the time required to accomplish this coupling reaction is quite different with these copper salts. In the case of Cu(OTf)2