Hegedus Indole Synthesis: Intramolecular Nucleopalladation of ortho-Allyl Aryl Nucleophiles

Key words

indoles - aminopalladation - palladium

Significance

Indoles are widely found within natural products, derivatives of which are commonly used as therapeutic agents for a broad range of indications. Hegedus and co-workers report an efficient synthesis of indoles (and other) heterocycles from the cyclization of aryl nucleophiles bearing an ortho-allyl group. The aminopalladation chemistry of Hegedus has been employed in the synthesis of ergot alkaloids and has inspired additional nucleo­palladation methodologies to be developed.

Comment

Although the yields are not document­ed in detail, the scope of this aminopalladation was established towards heterocycles including to carb­azole, indoline, dihydroquinoline, tetrahydroisoquinoline, and isocoumarin derivatives. Hegedus and co-workers published a follow-up report in 1978, outlining a catalytic methodology to perform the same reaction, employing benzoquinone as an oxidant to regenerate the necessary Pd(II) catalyst.

Publication History

Article published online:
08 December 2023