Ullmann coupling, Claisen rearrangements

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 construction of allyl vinyl ether 47 via an Ullmann coupling was followed by the Claisen rearrangement to deliver oxindole derivative 48 as reported by Kobayashi and co-workers. 

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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