Photocatalytic Dearomative Intermolecular [2 + 2] Cycloaddition of Heterocycles for Building Molecular Complexity was written by Oderinde, Martins S.;Ramirez, Antonio;Dhar, T. G. Murali;Cornelius, Lyndon A. M.;Jorge, Christine;Aulakh, Darpandeep;Sandhu, Bhupinder;Pawluczyk, Joseph;Sarjeant, Amy A.;Meanwell, Nicholas A.;Mathur, Arvind;Kempson, James. And the article was included in Journal of Organic Chemistry in 2021.Name: Methyl 5-bromo-1H-indole-2-carboxylate This article mentions the following:
Indole and indoline rings are important pharmacophoric scaffolds found in marketed drugs, agrochems., and biol. active mols. The [2 + 2] cycloaddition reaction is a versatile strategy for constructing architecturally interesting, sp3-rich cyclobutane-fused scaffolds with potential applications in drug discovery programs. A general platform for visible-light mediated intermol. [2 + 2] cycloaddition of indoles with alkenes has been realized. A substrate-based screening approach led to the discovery of tert-butyloxycarbonyl (Boc)-protected indole-2-carboxyesters as suitable motifs for the intermol. [2 + 2] cycloaddition reaction. Significantly, the reaction proceeds in good yield with a wide variety of both activated and unactivated alkenes, including those containing free amines and alcs., and the transformation exhibits excellent regio- and diastereoselectivity. Moreover, the scope of the indole substrate is very broad, extending to previously unexplored azaindole heterocycles that collectively afford fused cyclobutane containing scaffolds that offer unique properties with functional handles and vectors suitable for further derivatization. DFT computational studies provide insights into the mechanism of this [2 + 2] cycloaddition, which is initiated by a triplet-triplet energy transfer process. The photocatalytic reaction was successfully performed on a 100 g scale to provide the dihydroindole analog. In the experiment, the researchers used many compounds, for example, Methyl 5-bromo-1H-indole-2-carboxylate (cas: 210345-56-5Name: Methyl 5-bromo-1H-indole-2-carboxylate).
Methyl 5-bromo-1H-indole-2-carboxylate (cas: 210345-56-5) belongs to indole derivatives. Indole, first isolated in 1866, and it is commonly synthesized from phenylhydrazine and pyruvic acid, although several other procedures have been discovered. In addition to indole, the strain-release chemistry worked for numerous substrates including amines, alcohols, thiols, carboxylic acids, imidazoles, and pyrazoles.Name: Methyl 5-bromo-1H-indole-2-carboxylate
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Preparation of Indole Containing Building Blocks for the Regiospecific Construction of Indole Appended Pyrazoles and Pyrroles