- Direct C-H bond (Hetero)arylation of thiazole derivatives at 5-position catalyzed by N-heterocyclic carbene palladium complexes at low catalyst loadings under aerobic conditions
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A highly efficient and practical protocol has been developed for the synthesis of 5-(hetero)arylated thiazole derivatives via an N-heterocyclic carbene palladium (Pd-NHC) complex catalyzed direct C-H arylation reaction. Utilization of this methodology, th
- Ma, Bei-Bei,Lan, Xiao-Bing,Shen, Dong-Sheng,Liu, Feng-Shou,Xu, Chang
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- Palladium-Catalyzed Arylation of Azole Compounds with Aryl Halides in the Presence of Alkali Metal Carbonates and the Use of Copper Iodide in the Reaction
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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 Cul 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 Cul to some extent without using the palladium species to give 2-arylazoles.
- Pivsa-Art, Sommai,Satoh, Tetsuya,Kawamura, Yoshiki,Miura, Masahiro,Nomura, Masakatsu
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p. 467 - 473
(2007/10/03)
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- Antibacterial monic acid derivatives
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A compound of the formula (I) STR1 wherein R is a group STR2 R1 is hydrogen, phenyl, C1-20 alkyl, C2-8 alkenyl or C2-8 alkynyl each of which may optionally be substituted; or C3-7 cycloalkyl, X is a divalent group --Y--C=C--, and Y is oxygen or sulphur, have antibacterial and/or antimycoplasmal activity.
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