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A Rh(III)-catalyzed additive-controlled regioselective [4 + 1] and [4 + 2] cyclization of benzoic acids with alkynyl esters/amides under electrochemical conditions has been developed for the synthesis of phthalides and isocoumarins. The selectivity for the product formation was attained by merely changing the additive. Employment of NaOAc in the reaction produces isocoumarins whereas AcOH favors phthalides. Cyclic voltammetry and control experiments reveal the mechanistic pathway of the reaction. [ABSTRACT FROM AUTHOR]

A one‐pot, three‐component, base‐mediated [3+2] cycloaddition reaction to synthesize 1H‐pyrrol‐3(2H)‐ones from readily available amino acid esters, aldehydes, and terminal alkynes was reported. Isolation of the intermediate and the detailed mechanistic study revealed the course of the reaction. This multi‐component reaction proceeds via imine formation followed by the nucleophilic addition of alkyne to form a propargylamine precursor. Base‐mediated conversion of propargylamine precursor into 1‐azadiene followed by in situ ketene formation leading to [3+2] cycloaddition that ultimately produces unusual 1H‐pyrrol‐3(2H)‐ones. [ABSTRACT FROM AUTHOR]

The objective of this study is to address the communication system design issues of Intelligent Vehicle Highway Systems (IVHS). The focus of Phase I of this research is the design for California Advanced Driver Information Systems (CADIS). The emphasis is on the architecture and topology aspects of the physical link and access layers connecting the moving layers with the fixed infrastructure. The work is divided into the following categories: Automatic Vehicle Identification (AVI), IVHS communications survey and functional requirements, modeling of IVHS fading channels, multiple-access performance analysis, simulation for IVHS communications, system layout and architectural tradeoffs, throughput/ delay analysis, and FM Subcarrier and the IVHS environment.

An efficient ionic liquid-supported (ILs) strategy is applied for the synthesis of substituted isoindolo[1,2-a]quinazoline under microwave irradiation. The ILs enhances the coupling capability of microwave flash heating in green organic synthesis. The acid-catalyzed heterocyclization of ionic liquid bounded 3-amino-4-[(alkylamino)methyl]benzoate was carried out with α-ketobenzoic acids or γ-ketoaliphatic acid to synthesize five and six member fused N-heterocycles. The one-pot heterocyclization proceeded via amidation between primary amines and 2-acylbenzoic acids or γ-ketoaliphatic acid, followed by the intramolecular dehydrocyclization with the keto group under microwave heating. The significant advantages in green synthesis by using ILs synthesis under controlled microwave dielectric heating are the dramatic reduction in reaction time, improved energy utilization, simple purification, and increasing the productivity of desired compounds.

The S100A1 protein in humans is a calcium-binding protein. Upon Ca2+ binding to S100A1 EF-hand motifs, the conformation of S100A1 changes and promotes interactions with target proteins. RAGE consists of three domains: the cytoplasmic, transmembrane, and extracellular domains. The extracellular domain consists of C1, C2, and V domains. V domains are the primary receptors for the S100 protein. It was reported several years ago that S100A1 and RAGE V domains interact in a pathway involving S100A1-RAGE signaling, whereby S100A1 binds to the V domain, resulting in RAGE dimerization. The autophosphorylation of the cytoplasmic domain initiates a signaling cascade that regulates cell proliferation, cell growth, and tumor formation. In this study, we used pentamidine and a newly synthesized pentamidine analog (WLC-4059) to inhibit the S100A1-RAGE V interaction. 1H-15N HSQC NMR titration was carried out to characterize the interaction between mS100A1 (mutant S100A1, C86S) and pentamidine analogs. We found that pentamidine analogs interact with S100A1 via 1H-15N HSQC NMR spectroscopy. Based on the results, we utilized the HADDOCK program to generate structures of the mS100A1–WLC-4059 binary complex. Interestingly, the binary complex overlapped with the complex crystal structure of the mS100A1–RAGE-V domain, proving that WLC-4059 blocks interaction sites between S100A1 and RAGE-V. A WST-1 cell proliferation assay also supported these results. We conclude that pentamidine analogs could potentially enhance therapeutic approaches against cancers. [ABSTRACT FROM AUTHOR]