Frustrated Lewis pair (FLP)-catalyzed hydrogenation of aza-Morita–Baylis–Hillman adducts and sequential organo-FLP catalysis

Herein we report the metal-free diastereoselective frustrated Lewis pair (FLP)-catalyzed hydrogenation of aza-Morita–Baylis–Hillman (aza-MBH) adducts, accessing a diverse range of stereodefined β-amino acid derivatives in excellent isolated yields (28 examples, 89% average yield, up to 90:10 d.r.). Furthermore, sequential organo-FLP catalysis has been developed. An initial organocatalyzed aza-MBH reaction followed by in situ FLP formation and hydrogenation of the electron-deficient α,β-unsaturated carbonyl compounds can be performed in one-pot, using DABCO as the Lewis base in both catalytic steps

Model selection based algorithm in neonatal Chest EIT

This paper presents a new method for selecting a patient specific forward model to compensate for anatomical variations in electrical impedance tomography (EIT) monitoring of neonates. The method uses a combination of shape sensors and absolute reconstruction. It takes advantage of a probabilistic approach which automatically selects the best estimated forward model fit from pre-stored library models. Absolute/static image reconstruction is performed as the core of the posterior probability calculations. The validity and reliability of the algorithm in detecting a suitable model in the presence of measurement noise is studied with simulated and measured data from 11 patients. The paper also demonstrates the potential improvements on the clinical parameters extracted from EIT images by considering a unique case study with a neonate patient undergoing computed tomography imaging as clinical indication prior to EIT monitoring. Two well-known image reconstruction techniques, namely GREIT and tSVD, are implemented to create the final tidal images. The impacts of appropriate model selection on the clinical extracted parameters such as center of ventilation and silent spaces are investigated. The results show significant improvements to the final reconstructed images and more importantly to the clinical EIT parameters extracted from the images that are crucial for decision-making and further interventions

Model Selection Based Algorithm in Neonatal Chest EIT

This paper presents a new method for selecting a patient specific forward model to compensate for anatomical variations in electrical impedance tomography (EIT) monitoring of neonates. The method uses a combination of shape sensors and absolute reconstruction. It takes advantage of a probabilistic approach which automatically selects the best estimated forward model fit from pre-stored library models. Absolute/static image reconstruction is performed as the core of the posterior probability calculations. The validity and reliability of the algorithm in detecting a suitable model in the presence of measurement noise is studied with simulated and measured data from 11 patients

A series of crystallographically characterized linear and branched σ-alkane complexes of rhodium : from propane to 3-methylpentane

We thank the EPSRC (EP/M024210, and the UK National Crystallography Service), the Leverhulme Trust (RPG-2015-447), and SGC Chemicals for funding, T. M. Boyd (York) for experimental assistance and useful discussions, and Dr. M. Chadwick (Imperial College) for the initial synthesis of [1-isoprene][BAr ] . This work used the ARCHER UK National Supercomputing Service ( http://www.archer.ac.uk ) and the Cirrus UK National Tier-2 HPC Service at the EPCC ( http://www.cirrus.ac.uk ) funded by the University of Edinburgh and the EPSRC (EP/P020267/1).Using solid-state molecular organometallic (SMOM) techniques, in particular solid/gas single-crystal to single-crystal reactivity, a series of σ-alkane complexes of the general formula [Rh(Cy2PCH2CH2PCy2)(ηn:ηm-alkane)][BArF4] have been prepared (alkane = propane, 2-methylbutane, hexane, 3-methylpentane; ArF = 3,5-(CF3)2C6H3). These new complexes have been characterized using single crystal X-ray diffraction, solid-state NMR spectroscopy and DFT computational techniques and present a variety of Rh(I)···H-C binding motifs at the metal coordination site: 1,2-η2:η2 (2-methylbutane), 1,3-η2:η2 (propane), 2,4-η2:η2 (hexane), and 1,4-η1:η2 (3-methylpentane). For the linear alkanes propane and hexane, some additional Rh(I)···H-C interactions with the geminal C-H bonds are also evident. The stability of these complexes with respect to alkane loss in the solid state varies with the identity of the alkane: from propane that decomposes rapidly at 295 K to 2-methylbutane that is stable and instead undergoes an acceptorless dehydrogenation to form a bound alkene complex. In each case the alkane sits in a binding pocket defined by the {Rh(Cy2PCH2CH2PCy2)}+ fragment and the surrounding array of [BArF4]- anions. For the propane complex, a small alkane binding energy, driven in part by a lack of stabilizing short contacts with the surrounding anions, correlates with the fleeting stability of this species. 2-Methylbutane forms more short contacts within the binding pocket, and as a result the complex is considerably more stable. However, the complex of the larger 3-methylpentane ligand shows lower stability. Empirically, there therefore appears to be an optimal fit between the size and shape of the alkane and overall stability. Such observations are related to guest/host interactions in solution supramolecular chemistry and the holistic role of 1°, 2°, and 3° environments in metalloenzymes.Peer reviewe

Straightforward and controlled synthesis of porphyrin-phthalocyanine-porphyrin heteroleptic triple-decker assemblies

A versatile and straightforward protocol is disclosed for controlled synthesis of complex lanthanide-bridged heteroleptic porphyrin–phthalocyanine triple-decker assemblies. Two porphyrins, linked by a flexible spacer chain of intermediate length, sequentially capture lanthanide ions and a phthalocyanine to efficiently form the triple-decker complex. The bridge directs assembly, but also controls the mobility of the central macrocycle and further imparts a fully eclipsed arrangement of all three rings

Complementary syntheses giving access to a full suite of differentially substituted phthalocyanine-porphyrin hybrids

Phthalocyanines and porphyrins are often the scaffolds of choice for use in widespread applications. Synthetic advances allow bespoke derivatives to be made, tailoring their properties. The selective synthesis of unsymmetrical systems, particularly phthalocyanines, has remained a significant unmet challenge. Porphyrin-phthalocyanine hybrids offer the potential to combine the favorable features of both parent structures, but again synthetic strategies are poorly developed. Here we demonstrate strategies that give straightforward, controlled access to differentially substituted meso-aryl-tetrabenzotriazaporphyrins by reaction between an aryl-aminoisoindolene (A) initiator and a complementary phthalonitrile (B). The choice of precursors and reaction conditions allows selective preparation of 1:3 Ar-ABBB and, uniquely, 2:2 Ar-ABBA functionalized hybrids

Synthesis and solid-state characterisation of 4-substituted methylidene oxindoles

Background 4-substituted methylidene oxindoles are pharmacologically important. Detailed analysis and comparison of all the interactions present in crystal structures is necessary to understand how these structures arise. The XPac procedure allows comparison of complete crystal structures of related families of compounds to identify assemblies that are mainly the result of close-packing as well as networks of directed interactions. Results Five 4-substituted methylidene oxindoles have been synthesized by the Knoevenagel condensation of oxindole with para-substituted aromatic aldehydes and were characterized in the solid state by x-ray crystallography. Hence, the structures of (3E)-3-(4-Bromobenzylidene)-1,3-dihydro-2H-indol-2-one, 3a, (3E)-3-(4-Chlorobenzylidene)-1,3-dihydro-2H-indol-2-one, 3b, (3E)-3-(4-Methoxybenzylidene)-1,3-dihydro-2H-indol-2-one, 3c, (3E)-3-(4-Methylbenzylidene)-1,3-dihydro-2H-indol-2-one, 3d and (3E)-3-(4-Nitrobenzylidene)-1,3-dihydro-2H-indol-2-one, 3e, were elucidated using single crystal X-ray crystallography. Conclusions A hydrogen bonded dimer molecular assembly or supramolecular construct was identified in all the crystal structures examined along with a further four 1D supramolecular constructs which were common to at least two of the family of structures studied. The 1D supramolecular constructs indicate that once the obvious strong interaction is satisfied to form hydrogen bonded dimer it is the conventionally weaker interactions, such as steric bulk and edge-to-face interactions which compete to influence the final structure formation

Comfort radicalism and NEETs: a conservative praxis

Young people who are not in education, employment or training (NEET) are construed by policy makers as a pressing problem about which something should be done. Such young people's lack of employment is thought to pose difficulties for wider society in relation to social cohesion and inclusion and it is feared that they will become a 'lost generation'. This paper(1) draws upon English research, seeking to historicise the debate whilst acknowledging that these issues have a much wider purchase. The notion of NEETs rests alongside longstanding concerns of the English state and middle classes, addressing unruly male working class youth as well as the moral turpitude of working class girls. Waged labour and domesticity are seen as a means to integrate such groups into society thereby generating social cohesion. The paper places the debate within it socio-economic context and draws on theorisations of cognitive capitalism, Italian workerism, as well as emerging theories of antiwork to analyse these. It concludes by arguing that ‘radical’ approaches to NEETs that point towards inequities embedded in the social structure and call for social democratic solutions veer towards a form of comfort radicalism. Such approaches leave in place the dominance of capitalist relations as well as productivist orientations that celebrate waged labour