ZnCl2 and Pd/C catalyzed synthesis of 2-substituted indoles

Synthesis of Indoles via Intermolecular and Intramolecular Cyclization by Using Palladium-Based Catalysts

As part of natural products or biologically active compounds, the synthesis of nitrogen-containing heterocycles is becoming incredibly valuable. Palladium is a transition metal that is widely utilized as a catalyst to facilitate carbon-carbon and carbon-heteroatom coupling; it is used in the synthesis of various heterocycles. This review includes the twelve years of successful indole synthesis using various palladium catalysts to establish carbon-carbon or carbon-nitrogen coupling, as well as the conditions that have been optimized.

Recent advances in the synthesis of indoles from alkynes and nitrogen sources

This review highlights ten years of success in the synthesis of indoles using alkynes and nitrogen sources as substrates.

Crystal structure of 1-(5-bromo-2-(4-methoxyphenyl)-1H-indol-7-yl)ethan-1-ol, C17H14BrNO2

C17H14BrNO2, monoclinic, C2/c (no. 15), a = 31.437(3) Å, b = 5.5224(5) Å, c = 16.6545(16) Å, β = 94.703(4)°, V = 2881.6(5) Å3, Z = 8, R gt(F) = 0.0251, wR ref(F 2) = 0.067, T = 173(2) K.

One-Pot Synthesis of Substituted Benzo[b]furans and Indoles from Dichlorophenols/Dichloroanilines Using a Palladium-Dihydroxyterphenylphosphine Catalyst

Disubstituted benzo[b]furans were synthesized by ortho-selective Sonogashira coupling of dichlorophenols and terminal alkynes, followed by cyclization and Suzuki-Miyaura coupling in one pot, using a palladium-dihydroxyterphenylphosphine (Cy-DHTP) catalyst. The use of substoichiometric amounts of tetrabutylammonium chloride was effective in accelerating the Suzuki-Miyaura coupling. This protocol was also successfully applied to the one-pot synthesis of disubstituted indoles from dichloroaniline derivatives.