Ullmann coupling intramolecular

Chan has discovered a completely atropdiasteroselective synthesis of a biaryl diphosphine by asymmetric intramolecular Ullmann coupling or Fe(m)-promoted oxidative coupling. A chiral atropisomeric biaryl bisphosphine ligand 2 was synthesized through this central-to-axial chirality transfer.38 Recently, a xylyl-biaryl bisphosphine ligand, Xyl-TetraPHEMP, was introduced by Moran, and is found to be effective for the Ru-catalyzed hydrogenation of aryl ketone.39... 

The formation of the dibenzofuran nucleus by intramolecular Ullmann coupling of bis(2-iodophenyl) ethers has been little exploited, although the method offers potential. Mazere et al. have obtained 2,3,7,8-tetramethyl-dibenzofuran (47), and Carvalho and Sargent have obtained the dibenzofuran 21 (Scheme 6), by this method. 

The intramolecular Ullmann coupling of (/ )-36 in a completely diastereoselective reaction gives 37. The relative configuration at the newly introduced stereogenic axis had to be determined (see p 479)48. 

Ullmann Coupling Reaction. Axially dissymmetric biaryls have been synthesized via an intramolecular Ullmann coupling reaction of BINOL-derived aryl diesters (eq 6). In the example shown, the functionalized binaphthyl is obtained with high ee after hydrolysis of the intermediate 12-membered cyclic diester. 

Unsymmetrical biphenyls. This alcohol can be used as a template for synthesis of unsymmetrical biphenyls with substituents at or/Ao-posilions by an intramolecular Ullmann coupling. The two ester bonds of the coupling product can be cleaved selectively by NaOCHi or a primary amide. 

Al-tosyltryptamine with 2-methyl-5-oxazolecarbonyl chloride generated 1470a, which was cychzed to the C-D-E-F indole bis-oxazole model fragment 1471 via the A -acylamino ketone 1470b. Finally, the authors noted they were unable to effect an intramolecular Ullmann coupling of 1472 to prepare the B-C-D-F-G-H model fragment 1473. 

Scheme 31 Intramolecular Ullmann coupling and Claisen rearrangement...

The Kobayashi group has observed the intramolecular diastereoselective spirocyclization of racemic 2-haloindoles bearing a C3-tethered allylic alcohol [71, 72]. For example, CuCl-catalyzed intramolecular Ullmann coupling of 117 followed by spontaneous Claisen rearrangement of the intermediate pyranoindole 118 afforded, in a one-pot synthesis, the all-carbon quaternary center of spiro-oxindole 119 in 95% de (Scheme 31). The methodology has been extended to the synthesis of hexahydropyrroloindoles, e.g., ( )-debromoflustramine B and E. 

The synthetic and kinetic regularities of the amino-Claisen rearrangement were studied for the transformation of 2,5-dimethyl-Af-(pent-3-en-2-yl)aniline." The products are obtained via conversion of a binary r-complex formed by the reaction of N-alkenylaniline hydrochloride with the hydrochloride of the solvent (2,5-dimethylaniline). Spirocyclic oxindoles have been prepared from iodoindoles via a sequential intramolecular Ullmann coupling and Claisen rearrangement." Nucleophilic ort/io-propargylation of aryl sulfoxides has been reported to occur by intermolecular delivery of the nucleophile to sulfur followed by an intramolecular relay to carbon in a... 

Miyamoto, J., Okawa, Y., Nakazaki, A., Kobayashi, S. (2006). Highly diastereoselective one-pot synthesis of spirocyclic oxindoles through intramolecular Ullmann coupling and Claisen rearrangement. Angewandte Chemie International Edition, 45, 2274-2277. 

Hirano, T, Iwakiri, K., Miyamoto, H., Nakazaki, A., and Kobayashi, S. (2009) Total synthesis of (-)-flustramine Bvio one-pot intramolecular Ullmann coupling and Claisen rearrangement Heterocycles, 79, 805-820. 

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