Estrogen Receptor β-Targeted Near-Infrared Inherently Fluorescent Probe: A Potent Tool for Estrogen Receptor β Research

Estrogen receptor β (ERβ) is associated with many diseases, and ERβ probes can help to reveal the complex role of ERβ and promote the development of ERβ-targeted therapy. Herein, we designed and synthesized the first ERβ-targeted near-infrared (NIR) inherently fluorescent probe P5, which showed the advantages of high ERβ selectivity, good optical properties, and excellent ERβ imaging capability in living cells. The probe was successfully utilized to explore ERβ motion characteristic, and for the first time, the diffusion coefficient of ERβ was obtained. Moreover, P5 was also successfully applied to the in vivo imaging of ERβ in the prostate cancer mice model. Therefore, this ERβ-targeted NIR probe might be employed as a potential tool for the research of ERβ and related diseases.

Sequential Sonogashira/intramolecular aminopalladation/cross-coupling of ortho-ethynyl-anilines catalyzed by a single palladium source: rapid access to 2,3-diarylindoles

We have developed a practical and efficient one-pot protocol for the synthesis of 2,3-diarylindoles via Pd-catalyzed bis-arylative cyclization of various o-ethynylanilines with aryl iodides. Mechanism studies showed that a Pd-catalyzed Sonogashira reaction took place firstly, giving an internal alkyne intermediate, which subsequently underwent intramolecular aminopalladation/cross-coupling to give access to 2,3-diarylindoles. The present methodology exhibits a broad substrate scope, producing various 2,3-diaryl indoles bearing two different aryl groups.

Chemoselective metal-free indole arylation with cyclohexanones

Elemental sulfur- and iodine reagent-mediated indole C3 arylations have been developed with cyclohexanones as the arylating reagent.

Ultrasound assisted Bradsher reaction in aqueous and non-aqueous media: First use of ultrasounds in electrophilic aromatic cyclisation leading to polyacenes

The present work describes the first use of ultrasounds in the Bradsher cyclisation of activated and non-activated ortho-formyl diarylmethanes. This reaction is also the first example of electrophilic, aromatic cyclisation assisted by ultrasounds which leads to pure polycyclic, fused aromatic hydrocarbons containing 3 and 4 fused rings in excellent yields. The reaction proceeds not only in aqueous but also in non-aqueous media at milder conditions (room temperature) and in much shorter reaction times than in conventional protocols.

[3 + 2]-Annulations of N-alkyl-3-substituted indoles with quinone monoketals catalysed by Brønsted acids

An organocatalytic dearomative [3 + 2]-annulation of 3-alkylindoles and quinone monoketals provided benzofuro[2,3-b]indolines, while the reaction with 3-phenylindole leads to 2,3-diarylindoles in moderate yields.

2,3-Diaryl-substituted indole based COX-2 inhibitors as leads for imaging tracer development

A series of 2,3-diaryl-substituted indoles containing a fluorine or methoxy group was synthesized via Fischer indole synthesis, McMurry cyclization, or Bischler–Möhlau reaction to identify potential leads for PET radiotracer development.

Relevance of sonochemistry or ultrasound (US) as a proficient means for the synthesis of fused heterocycles

Medicinal chemistry has been benefited by combinatorial chemistry and high throughput parallel synthesis. The use of sonochemistry under controlled conditions has been proved beneficial for medicinal chemistry and drug discovery process since it dramatically reduces reaction times, from days or hours to minutes. In addition, sonochemistry synthesis provides higher yields, lower cost, easy workups and greater purity as compared to lower yields, tedious workups, longer reaction times, lesser purity and termination of many by-products in the conventional thermal methods.

Rhodium(III)-catalyzed synthesis of cinnolinium salts from azobenzenes and alkynes: application to the synthesis of indoles and cinnolines

Versatile salts: A new rhodium-catalyzed synthesis of cinnolinium salts from various azobenzenes and alkynes under air is described. These salts readily transform into three important classes of products, including indoles, indoloindoles, and cinnolines (see scheme).

Fluorescent diarylindoles by palladium-catalyzed direct and decarboxylative arylations of carboxyindoles

Simple and brilliant: 1-Substituted 1H-indole-2-carboxylic acids efficiently undergo successive diarylation accompanied by C-H bond cleavage and decarboxylation upon treatment with aryl bromides in the presence of a palladium catalyst system to afford fluorescent 2,3-diarylindoles. This facile synthetic method provides a highly efficient blue emitter with a quantum yield of 0.97 in the solid state (see scheme).

2-Pyridin-2-yl-1H-indole derivatives: Synthesis, estrogen receptor binding affinity, and photophysical properties

A series of novel 2-pyridin-2-yl-1H-indole derivatives (4a-f) was prepared by intramolecular cyclodehydration of alpha-anilinyl (or 3-anisidyl)-2-pyridin-2-yl-ethanones (2a-f) and their optical spectroscopy and estrogen receptor (ER) binding properties were studied. These compounds showed long wavelength fluorescent emission, which is sensitive to solvent polarity and pH, while indol-6-ols 4b, e, and f displayed reasonably good binding affinities to ER.