Aromatic substrates with oxygen- and nitrogen-containing substituents undergo oxidative coupling with alkynes and alkenes under rhodium catalysis through regioselective C-H bond cleavage. Coordination of the substituents to the rhodium center is the key to activate the C-H bonds effectively. Various fused-ring systems can be constructed through these reactions.

The reactions of iodobenzene with azole compounds, 1,2-disubstituted imidazoles and 2-substituted oxazoles and thiazoles, were examined in the presence of catalytic amounts of Pd(OAc)2 and PPh3 in DMF using alkali metal carbonates as bases. It was found that the coupling products, 5-arylazoles, could be selectively produced in good yields by using Cs2CO3. In the case that their 2-position is unsubstituted, the site could also be arylated. In reactions using bromobenzene in place of iodobenzene, K2CO3 was also as effective as Cs2CO3. The addition of a stoichiometric amount of CuI appeared to specifically promote the reactions of thiazoles as well as those of thiophene derivatives. The reactions of 2-unsubstituted azole compounds with aryl iodides could be mediated by CuI to some extent without using the palladium species to give 2-arylazoles.

formed without an organic solvent, an important ecological advantage. In this case the functionalization of the silica with the correct balance of polyethers is critical (Figure 3). Use of hydrophilic PEO yielded only low rates and conversions. Nonloo 10% PEO/iO%PPO-SiOz iit rn 20%PEOSiOz 75 3E mol% 25 0

[structure: see text]. The direct oxidative coupling of benzoic acids with internal alkynes proceeds efficiently in the presence of a rhodium/copper catalyst system under air to afford the corresponding isocoumarin derivatives. The reaction forms no wastes except for water. Under similar conditions, the aerobic coupling with acrylates also takes place smoothly to produce 7-vinylphthalide derivatives via divinylation and subsequent cyclization.

Playing Reversi with H and N: A copper‐catalyzed intermolecular regioselective hydroamination of styrenes with polymethylhydrosiloxane and hydroxylamine derivatives has been developed. The catalysis accommodates challenging β‐substituted substrates. Moreover, the chiral biphosphine‐ligated copper complex successfully forms benzylamines with good enantiomeric ratios.