Sustainable multicomponent indole synthesis with broad scope

Abstract

The most preferred heterocyclic indole core was de novo assembled by an innovative 2-step reaction from inexpensive and broadly available anilines, glyoxal dimethyl acetal, formic acid and isocyanides involving an...

Kinetic resolution of substituted amido[2.2]paracyclophanes via asymmetric electrophilic amination

“…In addition, the Pd-catalyzed para -iodination of ( R p )- 1a with NIS afforded 16a in 72% yield with 97% ee, which was also the enantiomer of 12a . Furthermore, after release of the NH 2 group, the four-component reaction of the aniline moiety with glyoxal dimethyl acetal, formic acid, and benzyl isocyanide gave the indole-containing PCP derivative 17a 58 . The utilization of these planar chiral amido-PCP skeletons in the development of chiral organocatalysts was explored as well.…”

Indole frameworks via transition-metal-free annulation: a current perspective

“…In the next year, the authors developed a similar type of Ugi-4CR method for indole-2-amide derivatives. 68 The condensation of anilines 25 , isocyanides 26 , glyoxal dimethyl acetal 27 and formic acid 31 led to Ugi-adduct 32 , which then underwent acid-assisted (MsOH) cyclization to form indole-2-amides 33 . This transformation was mild, straightforward, economic and scalable, addressing many of the twelve principles of green chemistry.…”

Functionalized molecules via MCRs: applications in drug discovery and material science

“…For example, the classical Fischer indole synthesis is often performed under highly acidic refluxing conditions of the precondensed phenylhydrazone derivatives. 21 Our aim is to find a milder, sustainable and more effective indole syntheses. Therefore, in Chapter 1, an unprecedented mild, two-step synthesis of 2-tetrazole substituted indoles via the Ugi-tetrazole reaction combined with an acid induced ring closure in methanesulfonic acid is reported.…”