@article {48811, title = {Origin of optoelectronic contradictions in 3,4-cycloalkyl[c]-chalcogenophenes: a computational study}, journal = {Polymers}, volume = {15}, year = {2023}, month = {NOV}, pages = {4240}, type = {Article}, abstract = {

The planar morphology of the backbone significantly contributes to the subtle optoelectronic features of pi-conjugated polymers. On the other hand, the atomistic tuning of an otherwise identical pi-backbone could also impact optoelectronic properties systematically. In this manuscript, we compare a series of 3,4-cycloalkylchalcogenophenes by tuning them atomistically using group-16 elements. Additionally, the effect of systematically extending these building blocks in the form of oligomers and polymers is studied. The size of the 3,4-substitution affected the morphology of the oligomers. In addition, the heteroatoms contributed to a further alteration in their geometry and resultant optoelectronic properties. The chalcogenophenes, containing smaller 3,4-cycloalkanes, resulted in lower bandgap oligomers or polymers compared to those with larger 3,4-cycloalkanes. Natural bonding orbital (NBO) calculations were performed to understand the disparity alongside the contour maps of frontier molecular orbitals (FMO).

}, keywords = {chalcogenophene, DFT calculation, Morphology, optoelectronic properties, steric effect}, doi = {10.3390/polym15214240}, author = {Masilamani, Ganesh and Krishna, Gamidi Rama and Debnath, Sashi and Bedi, Anjan} } @article {49252, title = {One-pot synthesis of pyrazoles from sulfonyl hydrazides and alkynyl ketones using environmentally benign sulfonium iodate (I) reagent}, journal = {ChemistrySelect}, volume = {9}, year = {2024}, month = {OCT}, pages = {e202403249}, type = {Article}, abstract = {

Pyrazole is an omnipresent moiety in many natural products and pharmaceutically active compounds. Here, we have developed a simple and dynamic method for one-pot synthesis of substituted pyrazoles through the intramolecular cyclization of hydrazides and alkynyl ketones, using a novel sulfonium saltbased iodate (\& Iukcy;) reagent system. This method has the advantage that it proceeds in a one-pot, without isolating a less stable hydrazone intermediate. Hypervalent iodine-based reagents are an environmentally benign and greener option to toxic metal oxidants; they have an extensive application in metal-catalyst-free reactions, and this reaction proceeds in less time with high yields.

}, keywords = {Deprotonation, One-pot reaction, Oxidative iodination, Pyrazole, S(N)2-type cyclization}, issn = {2365-6549}, doi = {10.1002/slct.202403249}, author = {Mishra, Akanksha and Talukdar, Mrinal and Krishna, Gamidi Rama and Begari, Eeshwaraiah} } @article {49643, title = {Organocatalyzed [4+2] cycloaddition of α,β-unsaturated ketones and isatylidene malononitrile: accessing spiro[3-arylcyclohexanone]oxindole derivatives}, journal = {RSC Advances}, volume = {14}, year = {2024}, month = {JAN}, pages = {2873-2877}, type = {Article}, abstract = {

Herein, we developed a series of compounds featuring spiro[3-arylcyclohexanone]oxindoles through Barbas [4 + 2] cycloaddition reactions between isatylidene malononitrile and alpha,beta-unsaturated ketones using l-proline as an organocatalyst. The reported methodology offers many advantages such as mild reaction conditions, diverse substrate scope with high yields, easy reaction setup, and use of easily synthesizable starting materials. An l-proline catalyzed-Barbas-[4 + 2]-cycloaddition reaction is reported for the synthesis of spiro[3-arylcyclohexanone]oxindole derivatives. The method can tolerate a diverse substrate scope with high yields.

}, doi = {10.1039/d3ra07652k}, author = {Patil, Baliram R. and Nichinde, Chandrakant B. and Chaudhari, Suryakant S. and Krishna, Gamidi Rama and Kinage, Anil K.} }