Melcher Michaela-Christina, Ivšić Trpimir, Olagnon Charlotte, Tenten Christina, Lützen Arne, Strand Daniel
Centre for Analysis and Synthesis, Lund University, Naturvetarvägen 14, 221 00, Sweden.
Kekulé-Institute of Organic Chemistry and Biochemistry, University of Bonn, Gerhard-Domagk-Str. 1, 53121, Bonn, Germany.
Chemistry. 2018 Feb 16;24(10):2344-2348. doi: 10.1002/chem.201704816. Epub 2017 Dec 14.
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.
平面手性5,11-二取代二苯并[a,e]环辛四烯（dbCOTs）已被开发出来，作为用于不对称应用的dbCOT配体的首个有用的手性同系物。本文描述了能够以对映体纯形式克级制备此类化合物的方法。在铑（I）催化的1,4-和1,2-芳基化反应中作为配体进行评估时，形成了叔和季立体中心，产率和选择性优异，对映体过量高达>99%。（-）-喷青霉素A关键环化前体的催化不对称合成突出了该体系在实际应用中的情况。
