Carbocycles are a key and widely present structural motif in organic compounds. The construction of structurally intriguing carbocycles, such as highly-strained fused rings, spirocycles or highly-functionalized carbocycles with congested stereocenters, remains challenging in organic chemistry. Cyclopropanes, cyclobutanes and cyclopentanes within such carbocycles can be synthesized through ring contraction. These ring contractions involve re-arrangement of and/or small molecule extrusion from a parental ring, which is either a carbocycle or a heterocycle of larger size. This review provides an overview of synthetic methods for ring contractions to form cyclopropanes, cyclobutanes and cyclopentanes en route to structurally intriguing carbocycles.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1039/d1cs01080h | DOI Listing |
J Chem Phys
January 2025
Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Nadia, Mohanpur 741246, WB, India.
In this paper, we demonstrate the performance of several density-based methods in predicting the inversion of S1 and T1 states of a few N-heterocyclic triangulene based fused ring molecules (popularly known as INVEST molecules) with an eye to identify a well performing but cost-effective preliminary screening method. Both conventional linear-response time-dependent density functional theory (LR-TDDFT) and ΔSCF methods (namely maximum overlap method, square-gradient minimization method, and restricted open-shell Kohn-Sham) are considered for excited state computations using exchange-correlation (XC) functionals from different rungs of Jacob's ladder. A well-justified systematism is observed in the performance of the functionals when compared against fully internally contracted multireference configuration interaction singles and doubles and/or equation of motion coupled-cluster singles and doubles (EOM-CCSD), with the most important feature being the capture of spin-polarization in the presence of correlation.
View Article and Find Full Text PDFPLoS One
January 2025
AIDS Clinical Center, National Center for Global Health and Medicine, Tokyo, Japan.
BICSTaR (BICtegravir Single Tablet Regimen) is an ongoing, observational cohort study assessing the virologic effectiveness and safety of bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) in treatment-experienced (TE) and treatment-naïve (TN) people with HIV across 14 countries over 24 months. We present 12-month outcomes from participants in the BICSTaR Japan cohort. Retrospective and prospective data were pooled from people with HIV aged ≥20 years receiving B/F/TAF within routine clinical care in Japan.
View Article and Find Full Text PDFJCI Insight
January 2025
Department of Pediatrics, Vanderbilt University Medical Center, Nashville, United States of America.
Determining how alveoli are formed and maintained is critical to understanding lung organogenesis and regeneration after injury. To study the cellular dynamics of this critical stage of lung development, we have used scanned oblique-plane illumination microscopy of living lung slices to observe alveologenesis in real time at high resolution over several days. Contrary to the prevailing notion that alveologenesis occurs by airspace subdivision via ingrowing septa, we find that alveoli form by ballooning epithelial outgrowth supported by contracting mesenchymal ring structures.
View Article and Find Full Text PDFBiomolecules
December 2024
Department of Pharmacy, Division of Pharmacognosy and Natural Products Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, 15771 Athens, Greece.
24-Masticadienonic acid (MNA) and 24-isomasticadienonic acid (IMNA) are the major triterpenic acids in Chios Mastic Gum (CMG), a resin derived from var. . Despite their promising pharmacological potential, limited information is available due to the complexity of isolating them in pure form.
View Article and Find Full Text PDFBMC Cardiovasc Disord
January 2025
Advanced Institute for Medical Sciences, Dalian Medical University, Dalian, 116044, China.
Background: The dried root of Inula helenium L., known as Inulae Radix in Mongolian medicine, is a widely used heat-clearing plant drug within the Asteraceae family. Alantolactone (ATL), a compound derived from Inulae Radix, is a sesquiterpene lactone with a range of biological activities.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!