Medicinal chemistry of indole derivatives: Current to future therapeutic prospectives.

Indole: A privileged scaffold for the design of anti-cancer agents.

Indole in the target-based design of anticancer agents: A versatile scaffold with diverse mechanisms.

Direct C–H functionalization of aromatic compounds is a useful synthetic strategy that has garnered much attention because of its application to pharmaceuticals, agrochemicals, and late-stage functionalization reactions on complex molecules. On the basis of previous methods disclosed by our lab, we sought to develop a predictive model for site selectivity and extend this aryl functionalization chemistry to a selected set of heteroaromatic systems commonly used in the pharmaceutical industry. Using electron density calculations, we were able to predict the site selectivity of direct C–H functionalization in a number of heterocycles and identify general trends observed across heterocycle classes.

Predictive Model for Site-Selective Aryl and Heteroaryl C-H Functionalization via Organic Photoredox Catalysis.

Surface organic ligands play a critical role in stabilizing atomically precise metal nanoclusters in solutions. However, it is still challenging to prepare highly robust ligated metal nanoclusters that are surface-active for liquid-phase catalysis without any pre-treatment. Now, an N-heterocyclic carbene-stabilized Au25 nanocluster with high thermal and air stabilities is presented as a homogenous catalyst for cycloisomerization of alkynyl amines to indoles. The nanocluster, characterized as [Au25 (i Pr2 -bimy)10 Br7 ]2+ (i Pr2 -bimy=1,3-diisopropylbenzimidazolin-2-ylidene) (1), was synthesized by direct reduction of AuSMe2 Cl and i Pr2 -bimyAuBr with NaBH4 in one pot. X-ray crystallization analysis revealed that the cluster comprises two centered Au13 icosahedra sharing a vertex. Cluster 1 is highly stable and can survive in solution at 80 °C for 12 h, which is superior to Au25 nanoclusters passivated with phosphines or thiols. DFT computations reveal the origins of both electronic and thermal stability of 1 and point to the probable catalytic sites. This work provides new insights into the bonding capability of N-heterocyclic carbene to Au in a cluster, and offers an opportunity to probe the catalytic mechanism at the atomic level.

/pdf/highly-robust-but-surface-active-an-n-heterocyclic-carbene-3jzn8uk3re.pdf

Highly Robust but Surface‐Active: An N‐Heterocyclic Carbene‐Stabilized Au25 Nanocluster

Indoles - A promising scaffold for drug development.

Synthesis and antimicrobial studies of novel bis(diamino)thiazoles

Novel photoactive 4-(4-chlorophenyl)-2-(1H-indol-3-yl)-6-substituted phenyl-2H-thiazolo[3,2-a][1,3,5]triazines were synthesized by the conjugate addition of ammonia to the indole-3-carbaldehyde Schiff bases followed by the condensation with 4-chlorobenzaldehyde. All the synthesized compounds were characterized by FT-IR, NMR, mass spectra and elemental analyses. Their antioxidant property, electrochemical and photophysical properties in different organic solvents were investigated. Comparative discussion on the photophysical properties of indole-3-carbaldehyde Schiff bases and 4-(4-chlorophenyl)-2-(1H-indol-3-yl)-6-substituted phenyl-2H-thiazolo[3,2-a][1,3,5]triazines has been described. The fluorescence quantum yield of Schiff bases (Φf = 0.66−0.70 in DMSO) found to be interestingly higher. High fluorescence quantum yield, large molar extinction coefficient, high stokes shift and smaller optical band gap positioning these new derivatives as an efficient metal free organic fluorescent and semiconductor material.

Synthesis and Fluorescence Properties of Novel indol-3yl-thiazolo[3,2-a][1,3,5]triazines and indole-3-carbaldehyde Schiff Bases

Synthesis and Cytotoxicity Studies of Thiazole Analogues of the Anticancer Marine Alkaloid Dendrodoine.

3-[2,4-Bis(arylamino)thiazol-5-oyl]indoles, as the analogs of the cytotoxic marine alkaloid dendrodoine, are synthesized from 1-(N,N'-diarylamidino)-3-arylthioureas which provided the four [S1-C2-N3-C4] ring atoms for the thiazole ring construction. The remaining carbon of the thiazole is sourced from 3-(2-bromoacetyl)indole. This [4+1] heterocyclization reaction provided novel 3-[2,4-bis(arylamino)thiazol-5-oyl]indoles, which are characterized by elemental analysis, IR, NMR and FAB Mass spectral data and showed moderate antibacterial activity.

http://nopr.niscair.res.in/bitstream/123456789/7541/1/IJCB%2049B%283%29%20323-326.pdf

S. L. Manju

Papers

Indoles - A promising scaffold for drug development.

Synthesis and antimicrobial studies of novel bis(diamino)thiazoles

Synthesis and Fluorescence Properties of Novel indol-3yl-thiazolo[3,2-a][1,3,5]triazines and indole-3-carbaldehyde Schiff Bases

Synthesis and Cytotoxicity Studies of Thiazole Analogues of the Anticancer Marine Alkaloid Dendrodoine.

Synthesis of bis(arylamino)thiazoloylindoles as novel analogs of dendrodoine