Cyclic polyacetylene (c-PA) is the cyclic derivative of the semiconducting linear polyacetylene. As with the linear derivative, cyclic polyacetylene is insoluble, making its characterization and processing challenging. Herein, we report the synthesis of c-PA via an indirect approach, employing ring-expansion metathesis polymerization of cyclic alkenes to form soluble polymer precursors. Subsequent retro-Diels−Alder elimination through heating provides c-PA. Dilute solution characterizations of the polymer precursors including 1 H nuclear magnetic resonance spectroscopy, gel permeation chromatography, and infrared and Raman spectroscopy confirm their cyclic structure and, by inference, the cyclic topology of the resulting c-PA. Solid-state thermal analyses via thermogravimetric analysis and differential scanning calorimetry reveal the chemical and physical transformations occurring during the retro-Diels−Alder elimination step and concurrent isomerization. Freestanding films are attainable via the soluble precursors, and when doped with I 2 , the films are semiconducting.

An efficient, eco-friendly, base free, one-pot, sequential protocol was developed for epoxide azidolysis and copper-catalyzed azide-alkyne cycloaddition using water as the solvent for the synthesis of 3-hydroxy-1-alkyl-3-[(4-aryl/alkyl-1H-1,2,3-triazol-1-yl)methyl]indolin-2-ones. The optimized reaction conditions have been generalized in the case of aromatic as well as aliphatic alkyne partners to afford good yields and high regioselectivity.

An efficient protocol was developed for the Friedel Crafts type thioarylation for the synthesis of aromatic/heteroaromaticthioamide derivatives from aryl isothiocyanates and electron rich aromatic/heteroaromatic molecules by employing the Lewis acid AlCl3 and the less hazardous solvent cyclohexane at 70°C. The developed protocol offers advantages over the previous methods such as use of stoichiometric amount of reactants/reagent, less toxic solvent, shorter reaction time and higher yields.

: Breast cancer is the second most commonly identified cancer in women in the United States after skin cancer. The past few years have seen a substantial increase in breast cancer awareness campaigns and active research in fields of diagnosis and targeted therapy. These factors have led to a better mechanistic understanding of the disease, detection at earlier stages and more personalized approach to treatment, ultimately causing a crucial increase in the survival rates after detection. However, with the advances in treatment, cases of patients developing primary resistance and acquired resistance are increasing. Most of the breast cancers which develop resistance to therapy are ER+ and are typically treated with tamoxifen and fulvestrant. These drugs either lower the levels of estrogen or inhibit the receptors for estrogen and prevent the tumor from spreading. Around one third of women treated with these drugs develop resistance to them, lowering their chances of survival. This has directed to the search of newer drug therapies to target advanced breast cancer and resistance. One of these efforts has resulted in the development of Palbociclib, a first in class inhibitor of cyclin dependent kinases 4 and 6 (CDK4 and CDK6), which was granted accelerated approval from FDA for combination therapy in postmenopausal women with ER+, HER2- metastatic breast cancer. This review is focused on the various aspects of “Palbociclib” including its synthesis, molecular modeling studies and efficacy and safety profile with clinical trials data.

Poly(vinyl ketones) (PVKs) have received considerable attention over the past few decades due to their unique photochemistry and photodegradation properties under ultraviolet (UV) light. Many PVKs rapidly undergo photodegradation under UV light. The side‐chain carbonyl moieties of PVKs permit photolysis through Norrish type I or Norrish type II reaction mechanisms and can also be readily modified by nucleophilic addition reactions. These unique properties lead to this class of polymers serving as versatile scaffolds for generating functional materials. This review captures the evolution of synthetic routes to access well‐defined PVKs, along with their photochemistry and photo‐degradation pathways, and discusses recent and potential applications of these photodegradable materials.

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