Reactivity Studies on a Diazadiphosphapentalene

The reactivity of diazadiphosphapentalene 1 towards various substrates was investigated. Reaction of 1 with ammonia–borane resulted in transfer hydrogenolysis concomitantly with the cleavage of a P?N bond. By treatment of 1 with 2,2,6,6‐tetramethylpiperidine‐1‐oxyl (TEMPO), oxidation took place at one of the phosphorus atoms of 1 , and a P^V/P^III mixed‐valence derivative was isolated. At the same time, it was demonstrated that only one of the phosphorus atoms in 1 behaves as an electron donor for electrophiles and Lewis acids. The former afforded an intramolecularly coordinated phosphine‐phosphenium species, whereas the latter demonstrates the ligand property of 1 . UV irradiation induced rearrangement of 1 into another example of another diazadiphosphapentalene.     

Innovation diffusion model with interactions and delays in adoption for two competitive products in two different patches

Ricerche di Matematica - The aim of the present paper, how the people behave towards the offer of two products in two different patches. In this work, an innovation diffusion model with...     

Effective Synthesis of 1,5-Disubstituted 2,1-Benzisothiazol-3(1H)-ones

A convenient and effective synthesis of novel 1,5-disubstituted 2,1-benzisothiazol-3(1H)-one derivatives is described. The approach involves nitration of inexpensive isatoic anhydride followed by its conversion to 5-nitro-2,1-benzisothiazol-3(1H)-ones in excellent yield and alkylation at the 1-position. The 5-amino group was further derivatized.      

Reaction of Chlorosulfonyl Isocyanate With 1,2-Diols: Rearrangement and Formation of Carbonates

1,2-Diols, 1a-e, upon reaction with chloro-sulfonyl isocyanate (CSI) gave the ketones, 3a-e Under similar experimental conditions, 1,2-diols, 1f-k, gave carbonyl compounds, 3f-k, carbonates, 6f-k, carboxamides, 7h, i, and the epoxide, 5i.     

Reaction of Olefins with Sulfuryl Chloride and Cyclic Ethers: An Efficient Synthesis of α-Chloroalkyl ω-Chloroalkyl Ethers

Olefins react with sulfuryl chloride in presence of cyclic ethers to form the corresponding α-chloroalkyl ω-chloroalkyl ethers     

Highly regioselective ring-opening of aziridines with arenesulfinates on water: a facile access to β-amino/vinyl sulfones

We have developed a LiBr catalyzed efficient synthesis of β-amino sulfones from readily available aziridines and sodium sulfinates in good to excellent yields. The synthetic potential of β-amino sulfones has also been demonstrated by their facile conversion to the corresponding vinyl sulfones. The use of water as reaction media, atom-economy and isolation of products by simple filtration in the case of solid β-amino sulfones are certain green virtues of the synthetic protocol.     

Target‐Directed Azide‐Alkyne Cycloaddition for Assembling HIV‐1 TAR RNA Binding Ligands

The highly conserved HIV‐1 transactivation response element (TAR) binds to the trans‐activator protein Tat and facilitates viral replication in its latent state. The inhibition of Tat–TAR interactions by selectively targeting TAR RNA has been used as a strategy to develop potent antiviral agents. Therefore, HIV‐1 TAR RNA represents a paradigmatic system for therapeutic intervention. Herein, we have employed biotin‐tagged TAR RNA to assemble its own ligands from a pool of reactive azide and alkyne building blocks. To identify the binding sites and selectivity of the ligands, the in situ cycloaddition has been further performed using control nucleotide (TAR DNA and TAR RNA without bulge) templates. The hit triazole‐linked thiazole peptidomimetic products have been isolated from the biotin‐tagged target templates using streptavidin beads. The major triazole lead generated by the TAR RNA presumably binds in the bulge region, shows specificity for TAR RNA over TAR DNA, and inhibits Tat–TAR interactions.     

Recent Progress in Inorganic Anions Templated Silver Nanoclusters: Synthesis,Structures and Properties

Over recent years, research on the ligand‐protected silver clusters have gained significant interest owing to their unique potential applications in catalysis, organic optoelectronics, and luminescent materials. However, the synthesis of structurally precise high‐nuclearity silver nanoclusters is still challenging and become one of the prime interests of chemists. The controllable synthesis of high‐nuclearity silver nanoclusters involves the ingenious use of capping ligands or/and templating agents. Thereinto, the main role of the templating agents is to promote the order arrangement of silver ions around them to form discrete molecules. Our lab has performed comprehensive studies on the ligand‐protected silver clusters in the past eight years. This review highlights recent progress in the use of inorganic template anions, silver precursors, solvents, and the ligand types in synthesizing high‐nuclearity silver nanoclusters. Furthermore, some interesting photo‐ and electrochemical properties revealed by silver clusters including luminescent thermochromism, electrical conductivity, and electrochemical reduction of H₂O₂ have been also summarized.