The Neber Route to Substituted Indoles

Abstract

Two complementary procedures have been developed for the conversion of the oximes of alpha-aryl ketones to azirines. On heating, the azirines rearrange smoothly to the corresponding indoles. The overall transformation offers a versatile route to indoles, complementary to the Fischer indole synthesis.

Visible‐Light‐Promoted Synthesis of Fluoroalkylated Oximes

“…Oximes are useful moieties that can be used as intermediates for synthesizing various organic compounds . In particular, oximes can be converted to various heterocycles including indole, isoquinoline, azirine, pyrrole, pyridine, and thiazole . Herein, we present a new synthetic method to prepare fluoroalkylated oximes, which are potential fluoroalkyl building‐blocks, from amino compounds and fluoroalkylated alkenes [Scheme b].…”

Indole synthesis: a review and proposed classification

“…We therefore developed 41 a general method for the conversion of an α-aryl ketone, such as 87 (Scheme 34) into the azirine 88 . Thermolysis of the azirine gave the indole 89 .…”

Three‐Membered Heterocycles. Structure and Reactivity

“…Similarly, vinyl azirine 274 undergoes thermal rearrangement to form exclusively the 2,5-disubstituted pyrrole 276, which is complementary to photolytic rearrangement, a process providing only the 2,3-product 275 [311,312]. Finally, Taber has reported on the high-yielding synthesis of indoles (e.g., 278) from arylazirines 277, which are themselves synthesized from the oximes of aryl ketones [313].…”