Regio- and Chemoselective Synthesis of Fully Substituted Furans

Abstract

Highly functionalized furyl-, indolyl-, and pyrrolylmagnesium reagents are efficiently prepared by direct C-H activation by using regio- and chemoselective magnesium amide bases, such as (tetramethylpiperidyl)magnesium chloride-lithium chloride (TMPMgCl˙LiCl) or bis(tetramethylpiperidyl)magnesium-bis(lithium chloride) (TMP₂Mg˙2LiCl), tolerated by a range of sensitive functional groups. These organometallic reagents readily react with various electrophiles, leading to polyfunctional heterocycles. Furthermore, the full functionalization of the sensitive furan scaffold can be achieved.

Key words

directed metalation - organometallic reagents - metal amides - magnesium - furan

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9

Determined by GC analysis of an iodolyzed reaction aliquot