In:
Green Chemistry, Royal Society of Chemistry (RSC), Vol. 23, No. 23 ( 2021), p. 9610-9616
Abstract:
We report a green cascade approach to prepare a variety of 3-aminoindole derivatives in good to excellent yields through an iron( iii )-catalyzed dehydrogenative cross-coupling reaction of 2-arylindoles and primary benzylamines under mild reaction conditions. Mechanistic studies show that a cascade reaction involves a tert -butyl nitrite (TBN)-mediated nitrosation of 2-substituted indoles and a 1,5-hydrogen shift to afford indolenine oximes, sequential iron( iii )-catalyzed condensation and a 1,5-hydrogen shift over four steps in a one-pot reaction. The reaction shows a broad substrate scope of indoles and benzylamines and tolerates a wide range of functional groups. Moreover, the reaction is easily performed at the gram scale without producing waste after the reaction is completed. The 3-aminoindole product is purified by simple extraction, washing, and recrystallization without flash column chromatography. A double imine ligand containing the 3-aminoindole unit is facile to obtain in a 52% yield in one step. The present method highlights readily available starting materials, a simple purification procedure, and the usage of cheap, nontoxic, and environmentally benign iron( iii ) catalysts.
Type of Medium:
Online Resource
ISSN:
1463-9262
,
1463-9270
Language:
English
Publisher:
Royal Society of Chemistry (RSC)
Publication Date:
2021
detail.hit.zdb_id:
1485110-6
detail.hit.zdb_id:
2006274-6
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