Control of Enantioselectivity in Rhodium(I) Catalysis by Planar Chiral Dibenzo[a,e]cyclooctatetraenes

Michaela-Christina Melcher; Trpimir Ivšić; Charlotte Olagnon; Christina Tenten; Arne Lützen; Daniel Strand

doi:10.1002/chem.201704816

Control of Enantioselectivity in Rhodium(I) Catalysis by Planar Chiral Dibenzo[a,e]cyclooctatetraenes

Chemistry. 2018 Feb 16;24(10):2344-2348. doi: 10.1002/chem.201704816. Epub 2017 Dec 14.

Authors

Michaela-Christina Melcher¹, Trpimir Ivšić¹, Charlotte Olagnon¹, Christina Tenten², Arne Lützen², Daniel Strand¹

Affiliations

¹ Centre for Analysis and Synthesis, Lund University, Naturvetarvägen 14, 221 00, Sweden.
² Kekulé-Institute of Organic Chemistry and Biochemistry, University of Bonn, Gerhard-Domagk-Str. 1, 53121, Bonn, Germany.

PMID: 29131428
DOI: 10.1002/chem.201704816

Abstract

Planar chiral 5,11-disubstiuted dibenzo[a,e]cyclo-octatetraenes (dbCOTs) have been developed as the first useful chiral homologs to dbCOT-ligands for asymmetric applications. Methods enabling the preparation of such compounds on a gram-scale in enantiomerically pure form are described. Evaluated as ligands in rhodium(I)-catalyzed 1,4- and 1,2-arylation reactions, tertiary and quarternary stereogenic centers were formed with excellent yields and selectivities of up to >99 % ee. A catalytic asymmetric synthesis of a key cyclization precursor to (-)-penifulvin A highlights the system in an applied context.

Keywords: asymmetric catalysis; cyclooctatetraenes; fenestrenes; planar chirality; rhodium.