A protocol for directly accessing geminal C-4 diarylated pyrazol-5(4H)-ones via tandem C-H aryne insertion and their inceptive neurobiological evaluation.

Geminal C-4 diarylation of substituted pyrazol-5(4H)-ones with in situ generated arynes as the aryl source has been achieved in a one-flask operation. All the newly accessed C4-gem-diarylated pyrazolone entities were found to be non-cytotoxic with varying AChE enzyme inhibitory activities and BBB permeability attributes that augur well for further advancement towards CNS therapeutics for untreatable disorders.

Diversified Stitching of Ynones with Oxindole-3-oxy acrylates: One-Flask Spiro-annulation Protocol toward Assorted 3H/5H-Spiro[furan-2,3'-indolin]-2'-ones.

Spiroannulation of oxindole-3-oxy acrylates with ynones involving two overlapping, base differentiated cascades has been observed. Initial exposure of ynones and oxindole 3-oxy acrylates to K2CO3 triggered a tandem Michael-Michael cascade to deliver a pair of spiroannulated diastereomers. Further exposure to LiHMDS led to deep restructuring through a second multistep cascade involving stereoselective recreation of the C3 quaternary center to furnish 3H-spiro[furan-2,3'-indolin]-2'-ones with functional amplification and scrambling. This new scaffold can be directly accessed in a one-flask operation from ynones and oxindole-3-oxy acrylates.

An Approach to Functionally Embellished o-Alkynylbenzoates or Furan-3(2H)-ones from Diynones and DMAD: Controlled Divergence and Product Selectivity.

The discovery of reaction regime controlled product diversification in a one-pot reaction between diynones and dimethyl-1,3-acetonedicarboxylate (DMAD) to selectively furnish either functionally unique pentasubstituted o-alkynylbenzoates or fully substituted furan-3(2H)-ones is delineated. The potential of these two versatile platforms to enter new utilitarian chemical space has also been explored.

Tandem Michael-anti-Michael Addition-Mediated Orthogonal Strapping of Diynones: Regioselective Spirocyclopentannulation of Oxindoles and Pyrazolones and DFT Validation.

An efficient protocol involving the transformation of sequentially generated recursive anions from heterocyclic precursors to orthogonally strap diynones through one pot transition-metal-free spirocyclopentannulation has been devised, employing oxindoles and pyrazolones as prototypical platforms. Insights into these regioselective tandem Michael-anti-Michael processes have been gleaned through DFT calculations.

A quick Chan-Lam C-N and C-S cross coupling at room temperature in the presence of square pyramidal [Cu(DMAP)4I]I as a catalyst.

A rapid and efficient protocol for C-N and C-S cross coupling has been developed using a new square pyramidal copper complex, [Cu(DMAP)4I]I. The complex was successfully synthesized via a disproportionation reaction of CuI and DMAP in DMSO. The catalytic activity of the complex was found to be excellent for Chan-Lam coupling reaction between aryl boronic acid and amine, amide, azide or thiol. The reaction could be carried out in the presence of only 2 mol% of the copper catalyst in methanol at room temperature within a short time.

Surfactant Dependent pH Controlled "off-on", "off-on-off" and "on-off" Fluorescent Switches Exhibited by N-Benzylidenenaphthalen-1-Amine.

N-benzylidenenaphthalen-1-amine (L) acts as pH dependent "off-on", "off-on-off" and "on-off" fluorescent switch in 1:1 (v/v) CH3CN:H2O depending on the presence of anionic sodiumdocdecyl sulphate (SDS), neutral triton X-100 (TX-100) and cationic cetyltrimethylammonium bromide (CTAB) surfactants respectively. DFT calculation shows the possibility of formation of L.H(+) due to protonation at immine N and L.OH(-) due to introduction of OH(-) group at immine C. The relative stability of these two cationic and anionic species depends on the charge environment provided by surfactants. This influences the photoinduced electron transfer (PET) processes involved and results in different switch behaviour.

A new simple Schiff base fluorescence "on" sensor for Al3+ and its living cell imaging.

The simple Schiff base (Z)-N-benzylidenenaphthalen-1-amine (L) acts as an effective fluorescence sensor for Al(3+) by "off-on" mode, and ca. 42 times enhancement in fluorescence intensity is observed. The detection limit of L towards Al(3+) is observed to be 5 × 10(-5) M. UV/Visible and fluorescence data as well as DFT calculations confirm 1:3 coordination between Al(3+) and L through N atoms in a pyramidal shape. L is employed for imaging the Al(3+) ion in living biological cells and for the determination of the Al(3+) ion in bovine serum albumin.