Palladium-catalyzed stereocontrolled ring-opening of 7-oxabenzonorbornadienes with organic carboxylic acids.

A palladium-catalyzed tandem reaction of 7-oxabenzonorbornadienes with organic carboxylic acids that provides cis-1,2-dihydro-l-naphthyl derivatives in moderate to good yields in a highly diastereoselective manner is described. A possible reaction mechanism involving syn acylation followed by insertion and diastereoselective ring-opening with 7-oxabenzonorbornadienes is proposed to account for the reaction.

Synthesis and DSSC application of BODIPY decorated triazole bridged and benzene nucleus cored conjugated dendrimers.

Conjugated dendrimers decorated with 5,5-difluoro-10-(4-(prop-2-ynyloxy)phenyl)-5H-dipyrrolo[1,2-c:1',2'-f][1,3,2]diazaborinin-4-ium-5-uide, usually known as boron dipyrromethene (BODIPY), have been synthesized and their application as photosensitizer in dye sensitized solar cells (DSSCs) has been evaluated. Third generation triazole bridged BODIPY dendrimers show higher light energy harvesting efficiency of 2.5% better than the first and second generation dendrimers, when used as a dye material in solar cells. The current intensity increases with an increase in the generation of the dendrimer as revealed by cyclic voltammetry. Fluorescence decay analysis shows that the relaxation times τ 1 and τ 2 increase as the dendrimer generation increases, however τ 2 for the third generation dendrimer decreases because of fluorescence quenching due to molecular crowding.

Discovery of new potential triplet acting inhibitor for Alzheimer's disease via X-ray crystallography, molecular docking and molecular dynamics.

The most common brain disorder of late life is Alzheimer's disease (AD), which is highly complicating dementia. There are several drug targets which are reported to control the severe level of AD; notably, acetylcholinesterase, ß-Secretase and glycogen synthase kinase enzymes are approached as a good drug targets for AD. Hence, the present study mainly focused to discover newly synthesized molecule (7-propyl-6H-pyrano[3,2-c:5,6-c']dichromene-6,8(7H)-dione) as a potential triplet acting drug for above said enzymes through the analysis of X-ray crystallography, molecular docking, molecular dynamics and quantum chemical calculation. The target drug molecule was crystallized in the monoclinic crystal structure with P21/n space group. The structure was solved by SHELXS and refined by SHELXL. The crystal packing is stabilized by C - H···O type of interactions. Further, the induced fit docking shows that the molecule has high docking score, glide energy, favorable hydrogen bonding and hydrophobic interactions on the protein targets. The molecular dynamics simulation was performed to understand the stability of the molecule in the presence of active site environment. Finally, quantum chemical calculation has been carried out for the molecule in gas phase and for the corresponding molecule lifted from the active site region. The structural comparison between gas phase and active site helps to understand the conformational modification of the molecule in the active site. Communicated by Ramaswamy H. Sarma.