We describe a Rh(I) catalyzed asymmetric ring opening of vinyl cyclopropanes using aryl boronic acids as C-nucleophiles. When ferrocene-based chiral bisphosphines are used as ligands, the products are obtained with regioselectivities typically 99:1 r.r.
View Article and Find Full Text PDFWe report chemically fueled oscillations of vesicles. The population cycling of vesicles is driven by their self-reproduction and collapse within a biphasic reaction network involving the interplay of molecular and supramolecular events. We studied the oscillations on the molecular and supramolecular scales and tracked vesicle populations in time by interferometric scattering microscopy and dynamic light scattering.
View Article and Find Full Text PDFImportance: The binary classification of spina bifida lesions as myelomeningocele (with sac) or myeloschisis (without sac) belies a spectrum of morphologies, which have not been correlated to clinical characteristics and outcomes.
Objective: To characterize spina bifida lesion types and correlate them with preoperative presentation and postoperative outcomes.
Design: Secondary analysis of images and videos obtained during fetoscopic spina bifida repair surgery from 2020-2023.
Introduction: Injury and subsequent thrombosis of the cerebral venous sinuses may be caused by closed head injuries secondary to a variety of different mechanisms. Skull fractures can lacerate or otherwise disrupt adjacent dural sinuses. The sequelae of such injuries may include thrombosis and either partial or total occlusion of the sinus, ultimately resulting in significant venous congestion.
View Article and Find Full Text PDFAsymmetric Suzuki-Miyaura cross-couplings with aryl boronic acids and allylic electrophiles are a powerful method to convert racemic mixtures into enantioenriched products. Currently, enantioconvergent allylic arylations are limited to substrates that are symmetrical about the allylic unit, and the absence of strategies to control regio-, E/Z- and enantioselectivity in acyclic allylic systems is a major restriction. Here, using a system capable of either conjugate addition or allylic arylation, we have discovered the structural features and experimental conditions that allow an acyclic system to undergo chemo- and regioselective, enantioconvergent allylic Suzuki-Miyaura-type arylation.
View Article and Find Full Text PDFCraniosynostosis is a developmental craniofacial defect in which one or more sutures of the skull fuse together prematurely. Uncorrected craniosynostosis may have serious complications including elevated intracranial pressure, developmental delay, and blindness. Proper diagnosis of craniosynostosis requires a physical examination of the head with assessment for symmetry and palpation of sutures for prominence.
View Article and Find Full Text PDFStudying autocatalysis - in which molecules catalyse their own formation - might help to explain the emergence of chemical systems that exhibit traits normally associated with biology. When coupled to other processes, autocatalysis can lead to complex systems-level behaviour in apparently simple mixtures. Lipids are an important class of chemicals that appear simple in isolation, but collectively show complex supramolecular and mesoscale dynamics.
View Article and Find Full Text PDFThe beneficial effects of physical activity on brain ageing are well recognised, with exerkines, factors that are secreted into the circulation in response to exercise, emerging as likely mediators of this response. However, the source and identity of these exerkines remain unclear. Here we provide evidence that an anti-geronic exerkine is secreted by platelets.
View Article and Find Full Text PDFPiperidines are frequently found in natural products and are of importance to the pharmaceutical industry. A generally useful asymmetric route to enantiomerically enriched 3-substituted piperidines remains elusive. Here we report a cross-coupling approach to enantioenriched 3-piperidines from pyridine- and sp-hybridized boronic acids.
View Article and Find Full Text PDFPlastic litter is an endemic problem within all regions, particularly cities. Much of this litter reaches the world's oceans with well documented environmental impacts. However, the monitoring of urban litter is often piecemeal at best.
View Article and Find Full Text PDFProgress to reduce plastic pollution has been painfully slow and the consequent damage to the natural environment and to human health is likely to increase further. This has been because the views and ways of working of four distinct stakeholder communities are not sufficiently well integrated. (1) Scientists, (2) industry, (3) society at large and (4) those making policy and legislation must in future find ways to work together.
View Article and Find Full Text PDFCholesterol is the precursor of bioactive plant metabolites such as steroidal saponins. An Australian plant, Dioscorea transversa, produces only two steroidal saponins: 1β-hydroxyprotoneogracillin and protoneogracillin. Here, we used D.
View Article and Find Full Text PDFObjective: Despite in utero spina bifida (SB) repair, more than two-thirds of patients with SB are unable to ambulate independently, and 1 in 4 children need surgery for tethered cord by school age. The objective of this study was to test the cryopreserved human umbilical cord (HUC) as an antiscarring material to reduce tethering and improve function in a modified in utero SB repair model.
Methods: An SB defect (L2-6 levels) without myelotomy was created in fetuses of timed-pregnant ewes at gestational day (GD) 75.
Objective: The aim of this study was to determine whether reversal of hindbrain herniation (HBH) on MRI following prenatal repair of neural tube defects (NTDs) is associated with reduced rates of ventriculoperitoneal (VP) shunt placement or endoscopic third ventriculostomy (ETV) within the 1st year of life.
Methods: This is a secondary analysis of prospectively collected data from all patients who had prenatal open repair of a fetal NTD at a single tertiary care center between 2012 and 2020. Patients were offered surgery according to inclusion criteria from the Management of Myelomeningocele Study (MOMS).
Unlabelled: Understanding the use behaviours of plastic items within households is important to enable informed policy development, particularly with the emerging and developing global plastic treaty. A survey of 400 permanent residents in Portsmouth aimed to identify the general trends in single-use plastic product (SUPP) use and disposal, and their personal motivations and barriers to reducing and recycling plastic. This included identifying common influencers of attitudes such as environmental values, situational characteristics, psychological factors and the individual demographic characteristics of residents.
View Article and Find Full Text PDFComplex cyclobutanes are important motifs in both bioactive molecules and natural products, yet their enantioselective preparation has not been widely explored. In this work, we describe rhodium-catalyzed enantioselective additions of aryl and vinyl boronic acids to cyclobutenone ketals. This transformation involves enantioselective carbometalation to give cyclobutyl-rhodium intermediates, followed by β-oxygen elimination to afford enantioenriched enol ethers.
View Article and Find Full Text PDFWe report a general, catalyst-controlled route to prostaglandin F2 and its analogues. The approach uses a Rh-catalyzed dynamic kinetic asymmetric Suzuki-Miyaura coupling reaction between a racemic bicyclic allyl chloride and alkenyl boronic esters bearing chiral alcohols to give cyclopentyl intermediates bearing 3 contiguous stereocenters. The route provides advanced intermediates in 99% ee as a single diastereoisomer in all cases examined, with the absolute stereochemistry of the cyclopentane core controlled by the ligand.
View Article and Find Full Text PDFAccess to carbocyclic C-nucleosides (CC-Ns) is currently restricted. The few methods available to make CC-Ns suffer from long syntheses and poor modularity, hindering the examination of potentially important chemical space. Here we report an approach to CC-Ns which uses an asymmetric Suzuki-Miyaura type reaction as the key C-C bond forming step.
View Article and Find Full Text PDFOrg Process Res Dev
November 2022
Csp-Csp Suzuki-Miyaura couplings (SMCs) are ubiquitous in the synthesis of small molecules, but analogous Csp-Csp bond-forming SMCs are rare, especially asymmetric variants. Recently, we developed a series of Rh-catalyzed couplings between racemic sp-hybridized allyl chlorides and heteroaryl boronic acids. Here, we demonstrate that these catalytic asymmetric reactions can be scaled-up to give over 100 g of a product.
View Article and Find Full Text PDFAvocado () is a member of the magnoliids, an early branching lineage of angiosperms that has high value globally with the fruit being highly nutritious. Here, we report a chromosome-level genome assembly for the commercial avocado cultivar Hass, which represents 80% of the world's avocado consumption. The DNA contigs produced from Pacific Biosciences HiFi reads were further assembled using a previously published version of the genome supported by a genetic map.
View Article and Find Full Text PDFTropane derivatives are extensively used in medicine, but catalytic asymmetric methods for their synthesis are underexplored. Here, we report Rh-catalyzed asymmetric Suzuki-Miyaura-type cross-coupling reactions between a racemic -Boc-nortropane-derived allylic chloride and (hetero)aryl boronic esters. The reaction proceeds an unexpected kinetic resolution, and the resolved enantiopure allyl chloride can undergo highly enantiospecific reactions with N-, O-, and S-containing nucleophiles.
View Article and Find Full Text PDFTospoviruses infect numerous crop species worldwide, causing significant losses throughout the supply chain. As a defence mechanism, plants use RNA interference (RNAi) to generate virus-derived small-interfering RNAs (vsiRNAs), which target viral transcripts for degradation. Small RNA sequencing and in silico analysis of capsicum and infected by tomato spotted wilt virus (TSWV) or capsicum chlorosis virus (CaCV) demonstrated the presence of abundant vsiRNAs, with host-specific differences evident for each pathosystem.
View Article and Find Full Text PDFRNA interference (RNAi) is a powerful tool that is being increasingly utilized for crop protection against viruses, fungal pathogens, and insect pests. The non-transgenic approach of spray-induced gene silencing (SIGS), which relies on spray application of double-stranded RNA (dsRNA) to induce RNAi, has come to prominence due to its safety and environmental benefits in addition to its wide host range and high target specificity. However, along with promising results in recent studies, several factors limiting SIGS RNAi efficiency have been recognized in insects and plants.
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