Accessing Heteroannular Benzoxazole and Benzimidazole Scaffolds via Carbodiimides Using Azide-Isocyanide Cross-Coupling as Catalyzed by Mesoionic Singlet Palladium Carbene Complexes Derived from a Phenothiazine Moiety.

The coupling of aryl and aliphatic azides with isocyanides yielding carbodiimides (-) were efficiently catalyzed by well-defined structurally characterized -(MIC)PdI(L) [MIC = 1-CHPh-3-Me-4-(CHN(CH)S)-1,2,3-triazol-5-ylidene, L = NCH (), MesNC ()], -(MIC)PdI (), and -(MIC)Pd(PPh)I () type palladium complexes, which incidentally mark the first instances of the use of mesoionic singlet palladium carbene complexes for the said application. As observed from the product yields, the catalytic activity varied in the order > ∼ > for these complexes. A detailed mechanistic studies indicated that the catalysis proceeded via a palladium(0) (- ) species.

Computational design of stapled peptide inhibitor against SARS-CoV-2 receptor binding domain.

Since its first detection in 2019, the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has been the cause of millions of deaths worldwide. Despite the development and administration of different vaccines, the situation is still worrisome as the virus is constantly mutating to produce newer variants some of which are highly infectious. This raises an urgent requirement to understand the infection mechanism and thereby design therapeutic-based treatment for COVID-19.

An approach to estimate the barrier height for magnetisation reversal in {Dy} SMMs using calculations.

Although ab initio CASSCF calculations yield a good numerical estimate of barrier height for magnetisation reversal for mononuclear Dy(iii) SIMs, obtaining a reliable value for higher nuclearity clusters such as {Dy2} are challenging. By analysing ab initio computed data of thirty-one different {Dy2} SMMs, we propose a model equation that relates the calculated barrier heights to the experimental values and offers a viable way to predict the barrier heights in {Dy2} SMMs.

Noble-Noble Strong Union: Gold at Its Best to Make a Bond with a Noble Gas Atom.

This Review presents the current status of the noble gas (Ng)-noble metal chemistry, which began in 1977 with the detection of AuNe through mass spectroscopy and then grew from 2000 onwards; currently, the field is in a somewhat matured state. On one side, modern quantum chemistry is very effective in providing important insights into the structure, stability, and barrier for the decomposition of Ng compounds and, as a result, a plethora of viable Ng compounds have been predicted. On the other hand.

Synthesis and Quantum Mechanical Studies of a Highly Stable Ferrocene-Incorporated Expanded Porphyrin.

We present the first evidence for an unusual stable metallocene-containing expanded porphyrinoid macrocycle that was synthesized by condensing one equivalent of 1,1'-bis[phenyl(2-pyrroyl)methyl]ferrocene with one equivalent of 5,10-di(p-tolyl)-16-oxa-15,17-dihydrotripyrrane under acid-catalyzed conditions. The formation of ferrocene-incorporated expanded porphyrin macrocycle was confirmed by HR-MS and 1D/2D NMR spectroscopy. The macrocycle was nonaromatic and displayed absorption bands in the region of 420-550 nm.

Morita-Baylis-Hillman and Rauhut-Currier reactions of conjugated nitroalkenes.

α-Functionalization of conjugated nitroalkenes and nitrodienes using various electrophiles in the presence of amine catalysts such as imidazole and DMAP and the synthetic applications of the products are reviewed. The electrophiles include formaldehyde, activated non-enolizable carbonyl compounds, activated imines, azodicarboxylates as well as activated alkenes such as nitroalkenes, MVK and acrylate. Reports on synthetic applications of the products, though only appearing in the last three years, highlight the potential of these multi-functional scaffolds to take part in diverse transformations such as Michael addition, cycloaddition and many cascade reactions leading to complex molecules including natural products.

Recent developments on domino metathesis reactions in India.

This review summarizes research work carried out in India on domino metathesis reactions using ruthenium-carbene complexes. This reaction has been widely used by synthetic chemists in India for the synthesis of polycyclic systems and complex molecular architectures.

Computational insight into a gold(I) N-heterocyclic carbene mediated alkyne hydroamination reaction.

A gold(I) N-heterocyclic carbene (NHC) complex mediated hydroamination of an alkyne has been modeled using density functional theory (DFT) study. In this regard, alkyne and amine coordination pathways have been investigated for the hydroamination reaction between two representative substrates, namely, MeC≡CH and PhNH(2), catalyzed by a gold(I) NHC based (NHC)AuCl-type precatalyst, namely, [1,3-dimethylimidazol-2-ylidene]gold chloride. The amine coordination pathway displayed a lower activation barrier than the alkyne coordination pathway.

Experimental and computational studies of selective recognition of Hg2+ by amide linked lower rim 1,3-dibenzimidazole derivative of calix[4]arene: species characterization in solution and that in the isolated complex, including the delineation of the nanostructures.

Amide linked lower rim 1,3-dibenzimidazole derivative of calix[4]arene, L has been shown to be sensitive and selective to Hg(2+) in aqueous acetonitrile solution based on fluorescence spectroscopy, and the stoichiometry of the complexed species has been found to be 1:1. The selectivity of L toward Hg(2+) has been shown among 11 M(2+) ions, viz., Mn(2+), Fe(2+), Co(2+), Ni(2+), Cu(2+), Zn(2+), Cd(2+), Hg(2+), Pb(2+), Ca(2+), and Mg(2+) studied, including those of the mercury group and none of these ions impede the recognition of Hg(2+) by L.

Rapid extraction and spectrophotometric determination of vanadium(IV) with thiothenoyltrifluoroacetone.

Thiothenoyltrifluoroacetone in carbon tetrachloride-butanol (1:1) is used for extraction and spectrophotometric determination of vanadium (IV) at pH 4.5-5. The greenish-yellow complex is measured spectrophotometrically at 450 nm.

Liquid-liquid extraction of lead(II) with tributyl phosphate.

Tributyl phosphate [30% solution in isobutyl methyl ketone (IBMK)] is used for the quantitative extraction of microgram amounts of lead from 3M hydrochloric acid containing lithium chloride (2M) as salting-out agent. It is then stripped from the organic phase with water and determined colorimetrically as its orange-red complex with 4-(2-pyridylazo)resorcinol at 520 nm. TBP alone cannot quantitatively extract lead in the absence of salting-out agents.

Liquid-liquid extraction of tungsten(VI) with mesityl oxide application to an alloy steel.

A new and simple method has been developed for the rapid extraction of tungsten(VI) with mesityl oxide. Quantitative extraction occurs from solutions 1M in hydrochloric acid and 12M in lithium chloride (as the salting-out agent) with 75% mesityl oxide in isobutyl methyl ketone. Tungsten is finally determined photometrically as the thiocyanate complex in the aqueous phase.