Rhodium-catalyzed arylation

The rhodium-catalyzed arylation of phenols with aryl halides occurs in the presence of phosphinites [PR2(OAr)] as a co-catalyst (Equation (59)).66 The phosphorus atom coordinates to the rhodium atom to facilitate the electrophilic substitution with the rhodium(m) species at the ortho-pos i on. 

In addition to aryl halides and triflates, organometallic reagents can be utilized for the catalytic arylation reaction. The rhodium-catalyzed arylation of arylpyridines proceeds with the use of tetraarylstannanes (Equation (67)).83 The ruthenium-catalyzed reaction of aromatic ketones with arylboronates affords the ortho-arylated aromatic ketones (Equation (68)).84... 

Rhodium-Catalyzed Arylation Reaction of Arylmetallic Reagents... 

Scheme 1. Rhodium catalyzed aryl-aiyl and aryl-propyl interchange between tertiary phosphines during propylene hydrogenation. (Conations 130°C, 2.5 hours 1000 ppm Rh as Rh(CO)2acetylacetonate 2.5 wt. percent each triphenylphosphine and tris-para-tolylphosphine 100 psia H2 propylene toluene solvent.)...

The mechanism of the rhodium catalyzed arylation of imines presumably occurs via an initial transmetallation to produce the arylrhodium species 59 (Figure 1.10). Aryl transfer followed by a second rhodium boron transmetallation (or protonation by water) completes the catalytic cycle. 

Scheme 1.36 Rhodium catalyzed arylation of N arenesulfonyl imines.

Lewis JC, Wu JY, Bergman RG, EUman JA (2006) Microwave-promoted rhodium-catalyzed arylation of heterocycles through C-H bond activation. Angew Chem Int Ed 45 1589-1591... 

Ueura K, Satoh T, Miura M (2005) Rhodium-catalyzed arylation using arylboron compounds efficient coupling of aryl halides and unexpected multiple arylation of benzonitrile. Org Lett 7 2229-2231... 

The synthesis of fused oxepines by transition metal-catalyzed reactions continues to be a major method for the formation of this heterocyclic system and can be separated into two types of transformations, those that react as tethered ethers and those that involve the reaction of an alcohol to form the seven-membered ring. The cyclization of tethered ethers included Heck cyclization (14EJO4053, 14CEJ17119), rhodium-catalyzed arylation of alkynes... 

Figure 8.4 Examined ligands in the rhodium-catalyzed arylation of imines.

The rhodium-catalyzed arylation of heterocycles was also proposed to proceed by an electrophihc aromatic pathway [83]. When using [RhCl(CO) P[OCH(CF3)2]3 2... 

Scheme 10.137 Rhodium-catalyzed arylation/cross-coupling reaction initiated by an inter-molecular carborhodation step [114].

Scheme 6.19 Rhodium-catalyzed arylation of N-protected ketimines, as described by Hayashi s group [24],...

Scheme 6.20 Rhodium-catalyzed arylation of cyclic W-sulfonyl ketimines using arylboroxines and the corresponding ring-opening step leading to the synthesis of chiral (triaryl)-methylamines, as described by...

Scheme 6.22 Rhodium-catalyzed arylation of N-benzyl nicotinate salts, as described by Nadeau and coworkers [27],...

In 2010, Hu and coworkers [14] reported an interesting innovation regarding the rhodium-catalyzed aryl addition to aldehydes. Using 2-formylbenzoates as substrates and arylboronic acids, 3-substituted phthalides were efficiently obtained with rhodium-spinol-based phosphites... 

Scheme 7.16 Upgraded catalytic conditions for the rhodium-catalyzed arylation of p-anisaldehyde, as described by Darses, Genet, and coworkers [26].

Nishimura T, Katoh T, Hayashi T (2007) Rhodium-catalyzed aryl transfer from trisubstituted aryl methanols to a, P-unsaturated carbonyl compounds. Angew Chem Int Ed 46(26) 4937 939. doi 10.1002/anie.200700902... 

Rhodium-catalyzed arylative ring-opening/spiroannulation of (3-arylcyclo-butylidene)acetate 23 with NaBPh, involved one C-C bond cleavage, two C-H bond cleavages, and three C-C bond formations to afford ketone 24 possessing a l,l -spirobiindane skeleton (Scheme 3.8) [20]. 

Rhodium-catalyzed arylation of 2-(2-alkynylphenyl)cyclobutanone 39 proceeded with site-selective P-carbon elimination of the benzylic carbon to afford the seven-membered ring ketone 40 (Scheme 3.19) [31]. 

Secondary benzylic alcohols are often oxidized to the corresponding ketones under the palladium-catalyzed arylation conditions. In contrast, a unique rhodium-catalyzed arylation of diarylmethanols having a 2-(2-pyridiyl) moiety... 

In 2013, Ryu and coworkers reported a rhodium-catalyzed arylation of 2-aryloxybenzoic acids through decarbonylative intramolecular C-H functionalization (Scheme 6.14) [24]. The existence of AC2O andKl could significantly enhance the reactivity. Based on the control experiments, a mixed anhydride will be produced through the condensation reaction of carboxylic acid and AC2O, which oxidize the rhodium(I) catalyst to rhodium(III) species. 

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