Novel small molecule MRGPRX2 antagonists inhibit a murine model of allergic reaction.

Background: Activation of Mas-related G protein-coupled receptor X2 (MRGPRX2) is a crucial non-IgE pathway for mast cell activation associated with allergic reactions and inflammation. Only a few peptides and small compounds targeting MRGPRX2 have been reported, with limited information on their pharmacologic activity.

Objective: We sought to develop novel small molecule MRGPRX2 antagonists to treat MRGPRX2-mediated allergies and inflammation.

Discovery of small-molecule modulators of the secretin receptor: Purmorphamine as novel anti-hypertensive agent.

The Secretin/Secretin receptor (SCTR) axis is well-known for its important role in water/salt homeostasis and blood pressure control. Recent studies revealed that absence of Secretin could lead to hypertension in animals and the administration of external Secretin leads to a sharp drop in blood pressure. Therefore, Secretin receptor has emerged as a crucial drug target of interest.

(2-Ethylhexyl)sodium: A Hexane-Soluble Reagent for Br/Na-Exchanges and Directed Metalations in Continuous Flow.

We report the on-demand generation of hexane-soluble (2-ethylhexyl)sodium (1) from 3-(chloromethyl)heptane (2) using a sodium-packed-bed reactor under continuous flow conditions. Thus, the resulting solution of 1 is free of elemental sodium and therefore suited for a range of synthetic applications. This new procedure avoids the storage of an alkylsodium and limits the handling of metallic sodium to a minimum.

Silver-Catalyzed Enantioselective Sulfimidation Mediated by Hydrogen Bonding Interactions.

An enantioselective sulfimidation of 3-thiosubstituted 2-quinolones and 2-pyridones was achieved with a stoichiometric nitrene source (PhI=NNs) and a silver-based catalyst system. Key to the success of the reaction is the use of a chiral phenanthroline ligand with a hydrogen bonding site. The enantioselectivity does not depend on the size of the two substituents at the sulfur atom but only on the binding properties of the heterocyclic lactams.

A Chiral Phenanthroline Ligand with a Hydrogen-Bonding Site: Application to the Enantioselective Amination of Methylene Groups.

A silver-catalyzed amination is reported that occurs at the aliphatic C3-substituent of various quinolones and pyridones. The C-H amination reaction proceeded with high site- and enantioselectivity (14 examples, 83-97% ee). The key to its success is the use of a chiral phenanthroline ligand that is attached via an ethynyl linker to the 8-position of octahydro-1-4,7-methanoisoindol-1-one.

Luminescent Iridium(III) Pyridinium-Derived N-Heterocyclic Carbene Complexes as Versatile Photoredox Catalysts.

The development of novel luminescent iridium(III) complexes with highly tunable emission energy and versatile applications is of particular importance. In this Communication, a series of luminescent iridium(III) complexes supported by chromophoric pyridinium-derived N-heterocyclic carbene (NHC) ligands that display tunable emission from 516 to 682 nm were prepared. These complexes can be used as photocatalysts in photooxidation and photoreduction reactions and could have potential applications in pH sensing.

Cobalt(II) Porphyrin-Catalyzed Intramolecular Cyclopropanation of N-Alkyl Indoles/Pyrroles with Alkylcarbene: Efficient Synthesis of Polycyclic N-Heterocycles.

A protocol on chemoselective cobalt(II) porphyrin-catalyzed intramolecular cyclopropanation of N-alkyl indoles/pyrroles with alkylcarbenes has been developed. The reaction enables the rapid construction of a range of nitrogen-containing polycyclic compounds in moderate to high yields from readily accessible materials. These N-containing polycyclic compounds can be converted into a variety of N-heterocycles with potential synthetic and biological interest.

Ruthenium-porphyrin-catalyzed diastereoselective intramolecular alkyl carbene insertion into C-H bonds of alkyl diazomethanes generated in situ from N-tosylhydrazones.

With a ruthenium-porphyrin catalyst, alkyl diazomethanes generated in situ from N-tosylhydrazones efficiently underwent intramolecular C(sp(3))-H insertion of an alkyl carbene to give substituted tetrahydrofurans and pyrrolidines in up to 99% yield and with up to 99:1 cis selectivity. The reaction displays good tolerance of many functionalities, and the procedure is simple without the need for slow addition with a syringe pump. From a synthetic point of view, the C-H insertion of N-tosylhydrazones can be viewed as reductive coupling between a C=O bond and a C-H bond to form a new C-C bond, since N-tosylhydrazones can be readily prepared from carbonyl compounds.

Ruthenium porphyrin catalyzed three-component reaction of diazo compounds, nitrosoarenes, and alkynes: an efficient approach to multifunctionalized aziridines.

A ruthenium porphyrin catalyzed three-component reaction of diazo compounds, nitrosoarenes, and alkynes gives multifunctionalized aziridines in good to high yields and with moderate to high diastereoselectivity.

Diastereoselective ruthenium porphyrin-catalyzed tandem nitrone formation/1,3-dipolar cycloaddition for isoxazolidines. Synthesis, in silico docking study and in vitro biological activities.

Ruthenium porphyrin catalyzes tandem nitrone formation/1,3-dipolar cycloaddition of diazo compounds, nitrosoarenes and alkenes to form isoxazolidines in good to high yields and with excellent regio-, chemo- and diastereo-selectivities. A broad substrate scope of alkenes is applicable to this protocol and various functional groups are compatible with the reaction conditions. In silico analysis and in vitro biological experiments revealed that some of the new isoxazolidines synthesized in this work could act as leukotriene A4 hydrolase inhibitors.