InCl3-Catalysed Conjugate Addition of Indoles with Electron-Deficient Olefins

Abstract

I n C l 3-C a t a l y s e d C o n j u g a t e A d d i t i o n o f I n d o l e s

InCl3: A Mild Lewis Acid but Efficient Reagent in Organic Synthesis

“…InCl 3 was used in the synthesis of aryl hydrazides, 2 2-haloamines, 3 cis-aziridine carboxylates, 4 chiral furan diol, 5 quinolines, 6 and homoallyl acetates. 7 Also it has been used in reductive Friedel-Crafts alkylation of aromatics with ketones or aldehydes, 8 for the reaction of acid chlorides with allylic tins, 9 for the insertion reactions of a-diazo ketones, 10 Biginelli reaction, 11 Mukaiyama aldol reactions, 1 imino Diels-Alder reactions, 1 in the conjugate addition of indoles with electrondeficient olefins, 18 for the bromolysis or iodolysis of a,bepoxycarboxylic acids 19 etc.…”

Metal halide hydrates as lewis acid catalysts for the conjugated friedel-crafts reactions of indoles and activated olefins

“…Alternatively, a third molecule of indole could be added to the bis-indolyl adduct 3n and 3o to form the tris-indolyl adduct 3p and 3q, respectively, as reported recently by Shi et al 23 ( Figure 1). All of the yields refer to isolated products after purification by column chromatography and the 1 H NMR, 13 C NMR and IR spectral data were in accordance with the proposed structures.…”

“…The spectroscopic 1 H NMR, 13 C NMR, IR data as well as the HRMS of selected compounds are provided as supplementary information and available free of charge at http:// jbcs.sbq.org.br, as PDF file.…”

An efficient synthesis of 3-diethoxyphosphoryl-4-(1H-indol-3-yl)-3,4-dihydrocoumarins: a convenient approach to 3-methylene-4-(indol-3-yl)-3,4-dihydrocoumarins

“…Among several reactions of indole, the reactions involving C-3 functionalization of indole with electron-deficient olefins have attracted and continue to attract interest from the synthetic community. While the reaction of indoles with highly electrophilic nitroolefins and enones to furnish β-(indol-3-yl) alkylated products has been widely investigated, [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] analogous reactions involving α,β-unsaturated esters to form 3-(indol-3-yl) alkanoates are rare. To date, two general strategies for the non-enantioselective synthesis of 3-(indol-3-yl) alkanoates have been reported.…”