General method for the synthesis of indoles

Gassman, Paul G.; Bergen, T. J. Van; Gilbert, David P.; Cue, Berkeley W.

doi:10.1021/ja00824a028

Cited by 164 publications

(60 citation statements)

References 8 publications

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“…According to the above-mentioned general procedure, the following indole derivatives were obtained and their m.p., 1 H-and 13 C-NMR were identical to those described in the literature. 2-Phenyl-1H-indole (entry 1, Table 2, in 68 and 66% yield), [26] 2-(4 -methyl)phenyl-1H-indole (entry 2, Table 2, in 67 and 62% yield), [27] 2-(4 -fluoro)phenyl-1H-indole (entry 3, Table 2, in 62 and 68% yield), [27] 2-(4 -methoxy)phenyl-1H-indole (entry 4, Table 2, in 65 and 58% yield), [28] 2,3,4,9-tetrahydro-1H-carbazole (entry 5, Table 2, in 98 and 92% yield), [29] 6,11-dihydro-5H-benzo[a]carbazole (entry 6, Table 2, in 69 and 65% yield), [30] 2-ethyl-3-methyl-1H-indole (entry 7, Table 2, in 81 and 80% yield), [31] 5-methyl-2-phenyl-1H-indole (entry 8, Table 2, in 70% yield), [27] 5-methyl-2-(4 -methyl)phenyl-1H-indole (entry 9, Table 2, in 72% yield), [32] 5-methyl-2-(4 -fluoro)phenyl-1H-indole (entry 10, Table 2, in 77% yield), [33] 6-methyl-2,3,4,9-tetrahydro-1H-carbazole (entry 11, Table 2, in 92% yield), [31] 8-methyl-6,11-dihydro-5H-benzo[a]carbazole (entry 12, Table 2, in 69% yield), [34] 8-methyl-5,10-dihydroindeno[1,2-b]indole (entry 13, Table 2, in 57% yield), [35] 4-methyl-2-phenyl-1H-indole (entry 14, Table 2, in 61 and 55% yield), [36] 5-methyl-2,3,4,9-tetrahydro-1H-carbazole (entry 16, Table 2, in 87 and 80% yield), [37] 2-(pyridin-4-yl)-1H-indole (entry 18, Table 2, in 86% yield). [38] According to the same procedure, 4-methyl-2-(4 -fluoro)phenyl-1H-indole (entry 15, …”

Section: General Procedures For Annulation Reaction Of O-haloanilines mentioning

confidence: 99%

Well‐defined NHCPd complex‐mediated intermolecular direct annulations for synthesis of functionalized indoles (NHC = N‐hetero‐cyclic carbene)

Jin

Guo

Qiu

et al. 2011

Applied Organom Chemis

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As alternatives to the common tertiary phosphine/Pd systems, well-defined N-heterocyclic carbene-Pd complexes have been proven to be highly efficient precatalysts for intermolecular direct annalution of o-haloanilines and ketones at lower catalyst loadings. A highly efficient and practical protocol for synthesis of functionalized indoles was developed using (IPr)Pd(acac)Cl as catalyst. Both o-bromoanilines and o-chloroanilines gave rise to efficient coupling under the reaction conditions. Related to acyclic ones, cyclic ketones coupled more effectively with o-haloanilines. With [Pd(IPr) 2 ] as catalyst, the base-sensitive groups including OH and CO 2 H groups could be tolerated.

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Section: General Procedures For Annulation Reaction Of O-haloanilines mentioning

confidence: 99%

Well‐defined NHCPd complex‐mediated intermolecular direct annulations for synthesis of functionalized indoles (NHC = N‐hetero‐cyclic carbene)

Jin

Guo

Qiu

et al. 2011

Applied Organom Chemis

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“…On the other hand, the catalytic performance of BAILs is dependent on the character of the cation and anion. For BAILs with HSO 4 -and H 2 PO 4 -as counteranions, the imidazolium cation with a n-butyl group on the alkyl side chain was more advantageous to the reac- [19][20][21][22][23][24][25][26][27][28][29][30][31] tion than the cation with a hydrogen on the N atom of the imidazolium, 92 %, 89 % and 82 %, 80 % yields, respectively (Entry 1 versus Entry 3 and Entry 4 versus Entry 6). For BAILs with the same [HMIm] + countercation, the catalytic performance of HMImNO 3 and HMImOTf were worse than that of the others; phenylhydrazone was formed in the first step, but the [3,3] sigmatropic rearrangement at 70°C, required for the completion of the one-pot Fischer indole synthesis, did not occur.…”

Section: Resultsmentioning

confidence: 99%

Fischer Indole Synthesis in Brønsted Acidic Ionic Liquids: A Green, Mild, and Regiospecific Reaction System

Yang

Luo

et al. 2007

Eur J Org Chem

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A novel one-pot Fischer indole synthesis approach has been developed by using Brønsted acidic ionic liquids as dual solvent-catalysts. Yields of 83-97 % were obtained after reaction in BMImHSO 4 at 70-110°C in 0.5-6 h, and exclusive formation of 2,3-disubstituted indoles was observed in the reaction of alkyl methyl unsymmetrical ketones. The indoles produced could be conveniently separated from the reaction

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“…[48][49][50][51] Protection of 4 by a tert-butoxycarbonyl (Boc) group followed by hydrogenation of the resultant 5 over Pd on carbon gave the 7-hydroxytryptamine 6. Reaction of 6 with methyl chloroacetate in the presence of K 2 CO 3 and KI in refluxing acetone, followed by deprotection of the resultant 7 using aqueous HCl produced the desired tryptamine 8 (Chart 5).…”

Section: Chemistrymentioning

confidence: 99%

Discovery of a Novel and Potent Human and Rat .BETA.3-Adrenergic Receptor Agonist, [3-[(2R)-[[(2R)-(3-Chlorophenyl)-2-hydroxyethyl]amino]propyl]-1H-indol-7-yloxy]acetic Acid

Harada

Hirokawa

Suzuki

et al. 2005

CHEMICAL & PHARMACEUTICAL BULLETIN

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1) This sub-classification has led to the development of b 1 -and b 2 -AR antagonists and/or agonists which have been useful for the treatment of cardiovascular diseases and asthma. In early 1980s, a third b-AR, initially referred to as "atypical"2) and later called b 3 -AR has been found in a number of species, including man, [3][4][5][6] and in 1989, the human, 7) rat, 8) and mouse 9) b 3 -ARs were first cloned and characterized. Like other b-ARs, b 3 -ARs belong to the G-protein-coupled receptor family that includes receptors with a common structure consisting of seven transmembrance-spanning connected by interhelical loops.10) The b 3 -AR is located on the surface of both white and brown adipocytes and is known to be stimulated by endogenous catecholamines, adrenalin, and noradrenaline. It has also been reported that b 3 -AR receptor plays a significant role in regulating lipolysis and thermogenesis in rodent and human adipose tissues. 11,12) Moreover, studies of b 3 -AR mRNA demonstrated that, b 3 -ARs exist in human heart, gall bladder, gastrointestinal tract, prostate, and urinary bladder detrusor tissue in addition to adipocytes. [13][14][15][16] Since the discovery of b 3 -AR, a number of laboratories have been engaged in developing potent and selective b 3 -AR agonists for the treatment of various metabolic and gastrointestinal diseases such as obesity, non-insulin dependent (Type-II) diabetes, irritable bowel syndrome, and urinary frequency and incontinence. [17][18][19][20][21] Early b 3 -AR agonists (the "first generation" of potent and selective rat b 3 -AR agonists) such as BRL 37344 (BRL 35135), [22][23][24] CL 316243, [25][26][27] and SR 58611A, 28) having a 3-chlorophenyl moiety in the left-hand side (LHS) and a carboxylic acid or an ester functionality in the right-hand side (RHS) as shown in Chart 1, have been reported to be effective anti-obesity and anti-diabetic agents in rodents.29) These compounds, through their potent agonistic activity for the b 3 -AR, stimulate lipolysis and energy expenditure and cause only a slight increase in heart rate (b 1 -AR activity) and weak muscle tremor (b 2 -AR activity). Unfortunately, some of these early b 3 -AR agonists developed for the treatment of metabolic disorders failed to produce similar effects in humans, due to a lack of selectivity and/or potency, or poor pharmacokinetics.30) Because of structural differences between human and rat b 3 -ARs with regard to the amino acid sequences of each receptor, activity at the rat b 3 -AR could not effectively predict that at the human b 3 -AR.31) Thus, a new generation of human b 3 -AR agonists with minimal side effects associated with activation of human b 1 -and b 2 -ARs has long been needed.A new generation of b 3 -AR agonists currently under preclinical development is represented by the tetrahydroisoquinoline 1, [32][33][34] SB 226552, 35,36) L 755507, 37) L 770644, 38,39) and LY-377604 40) (Chart 1). These compounds having both potent and full agonistic activity, and high selectivity at the human b...

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General method for the synthesis of indoles

Cited by 164 publications

References 8 publications

Well‐defined NHCPd complex‐mediated intermolecular direct annulations for synthesis of functionalized indoles (NHC = N‐hetero‐cyclic carbene)

Well‐defined NHCPd complex‐mediated intermolecular direct annulations for synthesis of functionalized indoles (NHC = N‐hetero‐cyclic carbene)

Fischer Indole Synthesis in Brønsted Acidic Ionic Liquids: A Green, Mild, and Regiospecific Reaction System

Discovery of a Novel and Potent Human and Rat .BETA.3-Adrenergic Receptor Agonist, [3-[(2R)-[[(2R)-(3-Chlorophenyl)-2-hydroxyethyl]amino]propyl]-1H-indol-7-yloxy]acetic Acid

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