LEADER 00000nam  2200337   4500 
001    AAI3225509 
005    20080111103758.5 
008    080111s2006                        eng d 
020    9780542799846 
035    (UMI)AAI3225509 
040    UMI|cUMI 
100 1  Mulrooney, Carol A 
245 10 Substrate scope of the asymmetric biaryl coupling 
       reaction. Asymmetric synthesis of a perylenequinone. 
       Progress toward the synthesis of cercosporin 
300    278 p 
500    Source: Dissertation Abstracts International, Volume: 67-
       07, Section: B, page: 3806 
500    Adviser: Marisa C. Kozlowski 
502    Thesis (Ph.D.)--University of Pennsylvania, 2006 
520    The Kozlowski group has developed an asymmetric copper-
       catalyzed oxidative biaryl coupling reaction using a novel
       1,5-diaza-cis-decalin ligand. This reaction gives good 
       yields and enantioselectivities for a number of 3-
       substituted 2-naphthols to yield new BINOL derivatives. A 
       substrate scope has been explored yielding insight into 
       the utility and reaction mechanism. Compounds that have 
       chelating groups in the 3-position are optimal for biaryl 
       coupling. A series of 3-sulfone-2-naphthols is described 
       for this reaction. The geometry and the electron-
       withdrawing character of the substituent are important for
       optimal coupling. The oxidation potential of the naphthol 
       is important for oxidation, electron-donating substituents
       placed in the system have an effect on the yield and 
       enantioselectivity of the reaction.* 
520    To explore the utility of the reaction further toward the 
       synthesis of natural products and their derivatives, a 
       series of highly substituted 2-naphthols was synthesized 
       in order to explore the synthesis of perylenequinone 
       natural products. Building on previously established 
       successful biaryl couplings of highly substituted 2-
       naphthols, a model system was developed toward the 
       synthesis of a perylenequinone derivative with the axial 
       chirality as the only chiral element. Initial progress via
       an ortho-quinone led to racemized product. A nucleophilic 
       aromatic substitution reaction was utilized to provide the
       oxygenation needed to transform the highly substituted 
       biaryl 47  to a chiral perylenequinone.* 
520    Steps toward the synthesis of the natural product 
       cercosporin were then developed. A mild decarboxylation 
       reaction was employed to remove the methyl esters that 
       were necessary for asymmetric biaryl coupling but not 
       present in the natural product. An allyl group was 
       introduced in the C7 position that would be later used to 
       introduce the chiral alcohols in the side chains. The 7-
       membered ring present in cercosporin was introduced by C5/
       C5' hydroxylation, then a selective deprotection strategy 
       followed by methylenation yielded intermediate  124. 
       Initial studies toward the introduction of the C7/C7' 
       chiral secondary alcohols proved disappointing. A survey 
       of chiral reductions was initiated on a model system with 
       moderate enantioselectivities achieved. Future plans are 
       proposed to introduce the chiral secondary alcohol via 
       reduction of a ketone with various chiral ligands.* 
520    *Please refer to dissertation for diagrams 
590    School code: 0175 
590    DDC 
650  4 Chemistry, Organic 
690    0490 
710 2  University of Pennsylvania 
773 0  |tDissertation Abstracts International|g67-07B 
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