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DOI: 10.1055/s-0029-1219217
Synthesis of Indanes by Enantioselective Direct Arylation
Contributor(s):Mark Lautens, Stephen G. NewmanETH Zürich, Switzerland
Enantioselective Palladium-Catalyzed Direct Arylations at Ambient Temperature: Access to Indanes with Quaternary Stereocenters
Angew. Chem. Int. Ed. 2009, 48: 9139-9142
Publication History
Publication Date:
21 January 2010 (online)
Key words
direct arylation - palladium - desymmetrization
Significance
Transition-metal-catalyzed C-H functionalization reactions are becoming increasingly practical; however, highly enantioselective variants are rare (see Review below). The authors have identified a catalytic system which allows for the desymmetrization of enantiotopic aryl C-H bonds using a palladium-catalyzed direct arylation.
Review
R. Giri, B.-F. Shi, K. M. Engle, N. Mangel, J.-Q. Yu Chem. Soc. Rev. 2009, 38, 3242-3272.
Comment
The key step in the catalytic cycle is proposed to involve a concerted metalation-deprotonation (CMD) reaction. The use of a chiral monodentate ligand is required to induce enantio-selectivity, and bulky taddol-based phosphoramidite ligands were optimal. The reaction is performed at room temperature using NaHCO3 as a base, making the process exceptionally mild.