The mechanism of intramolecular cycloadditions of azaxylylenes photogenerated via excited-state intramolecular proton transfer (ESIPT) in aromatic o-amido ketones and aldehydes bearing unsaturated functionalities was studied experimentally and computationally. In time-correlated single-photon counting experiments, no relation was found between lifetimes of singlet species and the nature of the ...

Cascade radical cyclisation involving homolytic aromatic substitution has been used to synthesise new tetracycles. Treatment of vinyl iodide radical precursors with Me(3)Sn. radicals (from hexamethylditin) yielded intermediate vinyl radicals which undergo 5-exo cyclisation onto suitably placed nitrile groups to yield intermediate iminyl radicals. The iminyl radicals undergo aromatic homolytic s...

We report the late-stage functionalization of multisubstituted pyridines and diazines at the position α to nitrogen. By this process, a series of functional groups and substituents bound to the ring through nitrogen, oxygen, sulfur, or carbon are installed. This functionalization is accomplished by a combination of fluorination and nucleophilic aromatic substitution of the installed fluoride. A...

Although silver nanoparticles are of great fundamental and practical interest, only one structure has been determined thus far: M4Ag44(SPh)30, where M is a monocation, and SPh is an aromatic thiolate ligand. This is in part due to the fact that no other molecular silver nanoparticles have been synthesized with aromatic thiolate ligands. Here we report the synthesis of M3Ag17(4-tert-butylbenzene...

Glycals 1 and 2 react with methoxybenzene in the presence of SnCLj forming ^-substituted C-glycosyl compounds 4 and 5 + 6 respectively. Under similar conditions l -Obenzoylor methyl pent-2-enopyranos-4-uloses (7) and (8) react with electron rich aromatic compounds furnishing either C-glycosyl compounds or C-2 aryl substituted products depending on the nature of the aromatic component as well as...

Relative yields of C-6, C-8. and C-6 and C-8 substituted catechins obtained from the reaction of (+ )-catechin or 3' 4',57-tetra-O-methvl-( + )-catechin with pyridinium hydrobromide-perbromide, bromine. p-hydroxybenzyl al~oh~I, or o-hydroxybenZyI alcohol showed differing selectivities depending upon the electrophile used. Ratios of C-6 to C-8 substituted products were 1 : 1.2 for the reaction o...

A study on the arylation of heteroatom nucleophiles by using activated haloarenes, with or without metal catalysts, is reported. A discussion concerning the involvement of traces of metals is presented, supported by an unexpected ''ligand'' effect in the absence of added metal catalysts. We believe that the frontier between nucleophilic aromatic substitution and catalysis will likely prove to b...

Curcumin, a poorly water-soluble bioactive compound, was successfully loaded into three different aromatic contents of hydroxypropylmethacrylamide (HPMA)-based polymeric micelles in order to develop water-soluble curcumin nanoformulations (Cur-Nano). The stability study of Cur-Nano was done by keeping the formulations at 4, 30, and 40 °C for 90 days. The physical appearance, curcumin remaining,...

IT sometimes happens in organic chemistry that a large body of related fact accumulates which seemingly cannot be rationalized on the basis of the currently available theoretical concepts. In such circumstances, substantial clarification may often be achieved by an approach which is novel only in application .to the system at band. The pieces of the puzzle may then fall into place and experimen...

Our computational and experimental investigation of the reaction of anisole with Cl2 in nonpolar CCl4 solution challenges two fundamental tenets of the traditional SEAr (arenium ion) mechanism of aromatic electrophilic substitution. Instead of this direct substitution process, the alternative addition-elimination (AE) pathway is favored energetically. This AE mechanism rationalizes the preferre...