Ullmann coupling diastereoselectivity

TABLE 8.30 DIASTEREOSELECTIVITY IN ULLMANN COUPLING REACTIONS (SCHEME 8.158), 466... 

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. 

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. 

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. 

The classical Ullmann reaction has also attracted renewed interest in recent years. Miyano has prepared optically enriched binaphthyl derivatives by intramolecular biaryl coupling, as shown in equation (9). " Diastereoselectivities of up to 70% have been obtained with a binaphthol chiral auxiliary in the linking chain. Intermolecular cross-coupling is best accomplished with preformed arylcopper compounds. "... 

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