Combined Directed ortho Metalation−Halogen Dance (HD) Synthetic Strategies. HD−Anionic ortho Fries Rearrangement and Double HD Sequences
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- 作者：Ricarda E. Miller ; Toni Rantanen ; Kevin A. Ogilvie ; Ulrich Groth ; Victor Snieckus
- 刊名：Organic Letters
- 出版年：2010
- 出版时间：May 21, 2010
- 年：2010
- 卷：12
- 期：10
- 页码：2198-2201
- 全文大小：195K
- 年卷期：v.12,no.10(May 21, 2010)
- ISSN：1523-7052
文摘
A general and efficient directed ortho metalation (DoM)−halogen dance (HD)−electrophile quench sequence for the synthesis of trisubstituted pyridyl O-carbamates is described. A second HD sequence furnishes highly functionalized tetrasubstituted pyridines. Furthermore, a hitherto unobserved double HD rearrangement is reported. Under similar LDA conditions, aromatic O-carbamates with OMe, Cl, and F substituents (4a−c) undergo either a HD−electrophile quench sequence, 4a−c → 18−20, or a HD−anionic ortho Fries rearrangement, 4a−c → 6a−c, respectively.