Nicolas Zeidan

Dearomative Indole Bisfunctionalization via a Diastereoselective Palladium-Catalyzed Arylcyanation

The first Pd-catalyzed dearomative indole bisfunctionalization via a diastereoselective arylcyanation is reported. This method facilitates the formation of diverse indoline scaffolds bearing congested stereocenters with high levels of diastereoselectivity. This also represents the first example of a cyanation mechanism involving a 2° benzylic Pd(II) intermediate.

Pd(0)‐Catalyzed Dearomative Diarylation of Indoles

We have developed a protocol for a Pd(0)-catalyzed dearomative syn 1,2-diarylation of indoles using readily available boroxines (dehydrated boronic acids) as coupling partners. This reaction proceeds efficiently using PtBu3 as the ligand to divergently access to fused indolines while minimizing the extent of direct Suzuki coupling. The scope of the reaction is remarkably broad and all products are obtained as single diastereomers in moderate to excellent yields. We have also compiled data which parallels the steric and electronic properties of both substrate and boroxine with the propensity to undergo the desired dearomative process over direct Suzuki coupling.

Palladium-Catalyzed Synthesis of 2-Cyanoindoles from 2-gem-Dihalovinylanilines

An efficient Pd(0)-catalyzed synthesis of 2-cyanoindoles from 2-gem-dihalovinylanilines is reported. Few methods have aimed to synthesize these scaffolds, which are found in many natural products and have high bioactivity. This protocol features a robust catalyst system utilizing Zn(TFA)2 to prolong the catalytic activity. Additionally, the amount of cyanide in the reaction phase is minimized by taking advantage of the solubility of Zn(CN)2 in a two-solvent mixture.

Magnetic bead-based electrochemical detection of interaction between epigallocatechin-3-gallate and STAT proteins

In this report, the interaction of the signal transducer and activator of transcription (STAT3 and STAT5) proteins with a green tea polyphenol epigallocatechin-3-gallate (EGCG) was investigated using differential pulse voltammetry (DPV) at carbon paste electrodes (CPEs). Superparamagnetic agarose nickel beads were modified with His-tagged STAT proteins and exposed to EGCG in solution. After magnetic separation of the beads, the electrochemical oxidation of the remaining EGCG in the supernatant was monitored at ∼0.18 V (vs. Ag/AgCl). The changes in the peak current signal displayed the interaction of EGCG with STAT proteins. Our electrochemical results were in agreement with the surface plasmon resonance (SPR) method that indicated the KD values of EGCG for STAT3 and STAT5 proteins were 19.33 ± 2.11 μM and 19.53 ± 2.37 μM, respectively. To the best of our knowledge, the electrochemical detection of interaction between STAT proteins and EGCG is reported here for the first time. The voltammetric method described here provides a promising platform for the rapid and cost-effective screening of small electro-active molecules that interact with STAT proteins and other clinically important proteins.