Palladium-Catalyzed Indole Ring Synthesis Larock

Palladium-Catalyzed Indole Ring Synthesis Larock 

Indole Ring Synthesis From Natural Products to Drug Discovery, First Edition. Gordon W. Gribble. 2016 John Wiley Sons, Ltd. Published 2016 by John Wiley Sons, Ltd. 

The Larock indolization was applied to solid-phase indole synthesis (Smith) [32], to phosphine-free (Guo [33], Djakovitch [34]) and salt-free (Djakovitch [34]) conditions, to 2-chloroanilines (Senanayake [35], Ackermann 

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Palladium-Catalyzed Indole Ring Synthesis Larock... 

Zhao and Larock have described the synthesis of carbazoles, indoles, and dibenzofurans 118 via a Ic type cyclization that follows a sequence of Pd-catalyzed cross-coupling of alkynes and aryl iodides 116, then nitrogen-directed palladium migration to an arylpalladium intermediate 117 that undergoes an intramolecular Mizoroki-Heck ring closure <06JOC5340>. 

Substituting the benzene ring with a double bond, Pd-catalyzed intramolecular alkoxylation of alkyne 122 also proceeded via an alkenyl palladium complex to form furan 123 instead of a benzofurans [99, 100]. In addition, 3-hydroxyalkylbenzo[fc]furans was prepared by Bishop et al via a Pd-catalyzed heteroannulation of silyl-protected alkynols with 2-iodophenol in a fashion akin to the Larock indole synthesis, [101]. 

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