COPPER CATALYZED ARYLATION

CHROMIUM TRIOXIDE-PYRIDINE COMPLEX, preparation in situ, 55, 84 Chrysene, 58,15, 16 fzans-Cinnamaldehyde, 57, 85 Cinnamaldehyde dimethylacetal, 57, 84 Cinnamyl alcohol, 56,105 58, 9 2-Cinnamylthio-2-thiazoline, 56, 82 Citric acid, 58,43 Citronellal, 58, 107, 112 Cleavage of methyl ethers with iodotri-methylsilane, 59, 35 Cobalt(II) acetylacetonate, 57, 13 Conjugate addition of aryl aldehydes, 59, 53 Copper (I) bromide, 58, 52, 54, 56 59,123 COPPER CATALYZED ARYLATION OF /3-DlCARBONYL COMPOUNDS, 58, 52 Copper (I) chloride, 57, 34 Copper (II) chloride, 56, 10 Copper(I) iodide, 55, 105, 123, 124 Copper(I) oxide, 59, 206 Copper(ll) oxide, 56, 10 Copper salts of carboxylic acids, 59, 127 Copper(l) thiophenoxide, 55, 123 59, 210 Copper(l) trifluoromethanesulfonate, 59, 202... 

Imines, sulfonamides, and hydantoins undergo copper-catalyzed arylation by aryllead triacetates in the same manner. In many cases, prior conversion of the N-H bonds into the corresponding sodium salts is recommended.43 44... 

Subsequently, a copper-catalyzed cross-coupling [with substoichiometric amounts of copper(l) iodide and N,N -dimethylethylenediamine (DMEDA)] between aryl halides and sulfoximines was developed [52]. In this case, both aryl bromides and aryl iodides reacted well. For the conversion of the former substrates an in-situ copper-catalyzed aryl Finkelstein reaction [53] had to be performed first, as shown in Scheme 2.1.1.22 for the preparation of 64 starting from bromobenzene (62). 

COPPER CATALYZED ARYLATION OF 0-DICARBONYL COMPOUNDS 2-(l-ACETYL-2-OXOPROPYL)BENZOIC ACID... 

Scheme 34 Copper-catalyzed arylation of aliphatic alcohols...

Two methodologies for the direct C-2 arylation of thiazoles have been reported. The first one is mediated by both palladium and copper <07T1970>. Thus, the C-2 arylation of thiazole and benzothiazole with aryl iodides is carried out using copper iodide (2 equiv.) and a catalytic amount of palladium acetate under base-free conditions. The other method involves copper-catalyzed arylation with aryl iodides in the presence of lithium t-butoxide <07JA12404>. In general, reactions with lithium tert-butoxide provide better yields than those with potassium fert-butoxide. In addition, arylation with phenyl bromide, chloride or tosylate fails to provide any desired arylation products. 

FIGURE 1.6 Copper-catalyzed aryl ether formation... 

Palladium and copper-catalyzed arylation of C-H bonds by aryl halide reagents is reviewed. The emphasis of the review is on directing-group-containing arene and alkane arylation catalyzed by palladium and on sp2 C-H bond arylation catalyzed by copper. Literature up to early 2009 is covered. 

Matsubara and Yoshida have shown that 9,10-di(pentafluorophenyl)anthra-cene can be synthesized by a copper-catalyzed arylation of pentafluorobenzene with dibromoanthracene [105], The reaction is only successful if silver oxide base is used. 

Do H-Q, Kashif Khan RM, Daugulis O (2008) A general method for copper-catalyzed arylation of arene C-H bonds. J Am Chem Soc 130 15185-15192 and references therein... 

Table 6. Influence of the base on the nickel or copper catalyzed arylation of 2-methoxyethanol (eqn. 6) a>. 

Copper catalyzed arylation of aliphatic primary amines now has become a test reaction for newly developed ligands. Many ligands were found to be effective for this transformation and some results are summarized in Table 9.1. As a cheap... 

A stoichiometric quantity of 1,10-phenanthroline (L13) was the first ligand used for copper-catalyzed arylation of imidazole with aryl iodides (Table 9.4, entry 1) [18]. As an ejctension of this methodology, Cu2O/4,7-dimethoxy-l,10-phenanthroline (LI4) was found to be more effective, the coupling reaction occur-ing at 80-110 °C in the presence of CS2CO3 and using n-PrCN as a solvent (entry 2 ) [19, 20]. 

Aliphahc alcohols were found to be less reactive toward ligand promoted copper-catalyzed arylation. But some successful examples have been reported by using special Hgands. Buchwald and coworkers discovered that if 1,10-phenanthroline (L13) was used as a Hgand, alkoxylation of aryl iodides with a wide range of... 

Scheme 1.5 Copper-catalyzed arylation of phenol (16) (Ullmann, 1905).

Scheme 1.7 Copper-catalyzed arylation of amide 21 (Goldberg, 1906).

In addition to Ullmann s copper-catalyzed [107] C(spVN bond formations using haloarenes, a remarkable complementary approach was developed by Chan and Lam during the 1990s using boron-based arylating reagents [108, 109). A detailed review by Andrew W. Thomas and Steven V. Ley on these oxidative copper-mediated and copper-catalyzed arylations, as well as their extension to alcohols [108, 110], is to be found in Chapter 4. 

Copper-Catalyzed Arylations of Amines and Alcohols with Boron-Based Arylating Reagents... 

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