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. 2007 Aug 31;72(18):6885-90.
doi: 10.1021/jo071156l. Epub 2007 Aug 9.

Welwistatin support studies: expansion and limitation of aryllead(IV) coupling reactions

Jibo Xia  1 , Lauren E Brown, Joseph P Konopelski
Affiliations

Welwistatin support studies: expansion and limitation of aryllead(IV) coupling reactions

Jibo Xia et al. J Org Chem. .

Abstract

Recent support studies on the total synthesis of the welwistatin system are described. The target step involves lead-mediated arylation of sterically demanding aryl groups and carbon acid coupling partners in order to establish the highly congested tetracyclic core structure. Type 7 beta-ketoesters and beta-ketonitriles were successfully arylated with a variety of ortho- and meta-substituted aryllead compounds generated by a halogen-boron-lead exchange sequence. The enolates of compounds 15, 19, and 25, each bearing all-carbon quaternary centers adjacent to the arylation site, failed to couple.

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Figures

Scheme 1
Scheme 1. Coupling Partners
Scheme 2
Scheme 2. Effect of Substitution
Scheme 3
Scheme 3. Synthesis of EP 15
Scheme 4
Scheme 4. Synthesis of EP 19
Scheme 5
Scheme 5. Synthesis of EP 25
Scheme 6
Scheme 6. Arylation of 15
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References

    1. Stratman K, Moore RE, Bonjouklian R, Deeter JB, Patterson GML, Shaffer S, Smith CD, Smitka TA. J Am Chem Soc. 1994;116:9935–9942.
    2. Jiminez JI, Huber U, Moore RE, Patterson GML. J Nat Prod. 1999;62:569–572. - PubMed
    1. Smith CD, Zilfou JT, Stratmann K, Patterson GML, Moore RE. Mol Pharm. 1995;47:241–247. - PubMed
    2. Zhang X, Smith CD. Mol Pharm. 1996;49:288–294. - PubMed
    1. Konopelski JP, Deng H, Schiemann K, Keane JM, Olmstead MM. Synlett. 1998:1105–1107.
    1. Wood JL, Holubec AA, Stoltz BM, Weiss MM, Dixon JA, Doan BD, Shamji MF, Chen JM, Heffron TP. J Am Chem Soc. 1999;121:6326–6327.
    1. Kaoudi T, Quiclet-Sire B, Seguin S, Zard SZ. Angew Chem Int Ed. 2000;39:731–733. - PubMed

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