Procedure for the Synthesis of Polysubstituted Carbazoles from 3-Vinyl Indoles

Abstract

A simple Brønsted acid catalyzed tandem reaction, including intermolecular nucleophilic addition, substitution and intramolecular cyclization, in a one-pot manner is described. Thirty two 2-indolyl substituted carbazoles are generated in good to excellent yields. Based on this tandem reaction strategy, the poly(1,4-carbazole) is prepared for the first time. Preliminary studies indicate that the poly(1,4-carbazole) has good thermostability and optical properties.

Chiral Calcium Phosphate Catalyzed Asymmetric Alkenylation Reaction of Arylglyoxals with 3-Vinylindoles

“…We found that this reaction could take place in the absence of phosphoric acid, which increased the difficulty to control the stereoselectivity. 14 Consequently, we turned our attention toward finding other highly efficient catalysts. According to Hosomi's work, CaCl 2 was a suitable catalyst for the aldol reaction of silyl enolates and arylgloxals.…”

“…Encouraged by the preliminary experimental results, chiral phosphoric acids 3b – g were screened in this reaction; however, better results were not obtained (Table , entries 2–7). We found that this reaction could take place in the absence of phosphoric acid, which increased the difficulty to control the stereoselectivity . Consequently, we turned our attention toward finding other highly efficient catalysts.…”

Selective Synthesis of 3-(9H-Carbazol-2-yl)indolin-2-ones and Spiro[tetrahydrocarbazole-3,3′-oxindoles] via a HOTf Catalyzed Three-Component Reaction

“…On the basis of the above results and the previously reported reactions, ,, a plausible reaction mechanism was relationally proposed in Scheme . In the first step, the Michael addition of 1-methylindole to 3-phenacylideneoxindole resulted in the major Michael adduct 7 and minor isomer 8 , which were gradually released to the starting material in lower concentrations by the acid catalyzed retro-Michael addition reaction.…”

Asymmetric Synthesis of 1,1,1-Triarylethanes by Chiral Imidodiphosphoric Acid Catalyzed Nucleophilic Addition of Pyrrole and Indoles to 3-Vinylindoles

“…In recent years, 3-vinylindoles have emerged as a kind of versatile chemical synthon in many asymmetric transformations, which is due to their chemical diversity through modifying the terminal alkene at the C3 position of an indole . Among them, 3-vinylindoles could participate in enantioselective addition reactions as electrophilic acceptors but, to a large extent, remained underdeveloped .…”