You Can Lead a Horse to Water: Mapping Seasonal Water Resources to Predict Wild Horse Movements on Utah Rangelands

All wild horse herd management areas in Utah overlap BLM grazing allotments. Although horses and cattle have similar dietary habits, both species rely heavily on predictable water sources during dry periods. The concentration of wildlife and livestock in mesic areas during droughts can become problems for farmers and livestock producers. We aimed to map the annual distribution of temporary surface water across Utah that cattle, horses, and wildlife could use. Herein we analyzed an 18-year record of satellite imagery to create a statewide map of seasonal surface-water availability for agricultural and wildlife management purposes

Aryloxide-facilitated catalyst turnover in enantioselective α,β-unsaturated acyl ammonium catalysis

The authors thank the European Research Council under the European Union's Seventh Framework Programme (FP7/2007-2013) ERC grant agreement no. 279850 (A.D.S) and the EPSRC (EP/J018139/1, A.M.) for funding. A.D.S. thanks the Royal Society for a Wolfson Research Merit Award.A new general concept for α,β-unsaturated acyl ammonium catalysis is reported that uses p-nitrophenoxide release from an α,β-unsaturated p-nitrophenyl ester substrate to facilitate catalyst turnover. This method was used for the enantioselective isothiourea-catalyzed Michael addition of nitroalkanes to α,β-unsaturated p-nitrophenyl esters in generally good yield and with excellent enantioselectivity (27 examples, up to 79% yield, 99:1 er). Mechanistic studies identified rapid and reversible catalyst acylation by the α,β-unsaturated p-nitrophenyl ester, and a recently reported variable-time normalization kinetic analysis method was used to delineate the complex reaction kinetics.Publisher PDFPeer reviewe

NHC-catalyzed enantioselective synthesis of β-trifluoromethyl-β-hydroxyamides

Authors acknowlege the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007-2013) ERC grant agreement no. 279850 (A.T.D.). We also thank the EPSRC UK National Mass Spectrometry Facility at Swansea University.The N-heterocyclic carbene (NHC) catalyzed formal [2+2] cycloaddition between α-aroyloxyaldehydes and trifluoroacetophenones, followed by ring-opening with an amine or reducing agent is described. The resulting β-hydroxy-β-trifluoromethyl amide and alcohol products are produced with reasonable diastereocontrol (typically ~70:30 dr) and excellent enantioselectivity, and can be isolated in moderate to good yield as a single diastereoisomer.Publisher PDFPeer reviewe

Isothiourea-catalyzed acylative kinetic resolution of tertiary α-hydroxy esters

Funding: ERC under the European Union's Seventh Framework Programme (FP7/2007–2013)/E.R.C. grant agreement no. 279850. The Chinese Scholarship Scheme and University of St Andrews are thanked for a CSC Scholarship (S.Q.). Universidad Autónoma de Madrid is thanked for a predoctoral fellowship (V.L.-M.). We thank the EPSRC Centre for Doctoral Training in Critical Resource Catalysis (CRITICAT, grant code EP/L016419/1) for funding (R.M.N.). A.D.S. thanks the Royal Society for a Wolfson Research Merit Award.A highly enantioselective isothiourea-catalyzed acylative kinetic resolution (KR) of acyclic tertiary alcohols has been developed. Selectivity factors of up to 200 were achieved for the KR of tertiary alcohols bearing an adjacent ester substituent, with both reaction conversion and enantioselectivity found to be sensitive to the steric and electronic environment at the stereogenic tertiary carbinol centre. For more sterically-congested alcohols, the use of a recently-developed isoselenourea catalyst was optimal, with equivalent enantioselectivity but higher conversion achieved in comparison to the isothiourea HyperBTM. Diastereomeric acylation transition state models are proposed to rationalize the origins of enantiodiscrimination in this process. This KR procedure has also been translated to a continuous flow process using a polymer-supported variant of the catalyst.Publisher PDFPeer reviewe

Enantioselective synthesis of 2,3-disubstituted trans-2,3-dihydrobenzofurans using a Brønsted base/thiourea bifunctional catalyst

The research leading to these results (D-J.B.A.; C. F.) has received funding from the ERC under the European Union's Seventh Framework Programme (FP7/2007-2013) / ERC grant agreement n° 279850. ADS thanks the Royal Society for a Wolfson Research Merit Award.The diastereo- and enantioselective synthesis of 2,3-disubstituted trans-2,3-dihydrobenzofuran derivatives (15 examples, up to 96:4 dr, 95:5 er) via intramolecular Michael addition has been developed using keto-enone substrates and a bifunctional tertiary amine-thiourea catalyst. This methodology was extended to include non-activated ketone pronucleophiles for the synthesis of 2,3-disubstituted indane and 3,4-disubstituted tetrahydrofuran derivatives.PostprintPeer reviewe

Horeau amplification in the sequential acylative kinetic resolution of (±)-1,2-diols and (±)-1,3-diols in flow

We gratefully acknowledge the University of Ferrara (Bando Giovani Ricercatori 2019) for financial support (AB). The Chinese Scholarship Scheme and University of St Andrews are thanked for a CSC Scholarship (S. Q.). Aix-Marseille University, CNRS, and ANR (Agence Nationale de la Recherche) (AMPLI project ANR-18-CE07-0036) are also gratefully acknowledged for funding (TD, XL and CB).The sequential acylative kinetic resolution (KR) of C2-symmetric (±)-1,2-syn and (±)-1,3-anti-diols using a packed bed microreactor loaded with the polystyrene-supported isothiourea, HyperBTM, is demonstrated in flow. The sequential KRs of C2-symmetric (±)-1,2-syn and (±)-1,3-anti-diols exploits Horeau amplification, with each composed of two successive KR processes, with each substrate class significantly differing in the relative rate constants for each KR process. Optimisation of the continuous flow set-up for both C2-symmetric (±)-1,2-syn and (±)-1,3-anti-diol substrate classes allowed isolation of reaction products in both high enantiopurity and yield. In addition to the successful KR of C2-symmetric (±)-1,2-syn and (±)-1,3-anti-diols, the application of this process to the more conceptually-complex scenario involving the sequential KR of C1-symmetric (±)-1,3-anti-diols was demonstrated, which involve eight independent rate constants.Publisher PDFPeer reviewe

Enantioselective N-heterocyclic carbene catalyzed formal [3+2] cycloaddition using α-aroyloxyaldehydes and oxaziridines

We thank the EPSRC Centre for Doctoral Training in Critical Resource Catalysis (CRITICAT, grant code EP/L016419/1) (R.W.F.K.) for funding. The European Research Council under the European Union’s Seventh Framework Programme (FP7/2007–2013) ERC Grant Agreement No. 279850 is also acknowledged. A.D.S. thanks the Royal Society for a Wolfson Research Merit Award.An enantioselective N-heterocyclic carbene catalysed formal [3+2] cycloaddition has been developed for the synthesis of oxazolindin-4-one products. The reaction of oxaziridines and α-aroyloxyaldehydes under N-heterocyclic carbene catalysis provides the formal cycloaddition products with excellent control of the diastereo- and enantioselectivity (12 examples, up to >95:5 dr, >99:1 er). A matched-mismatched effect between the enantiomer of the catalyst and oxaziridine was identified, and preliminary mechanistic studies have allowed the proposal of a model to explain these observations.Publisher PDFPeer reviewe

Isothiourea-catalyzed enantioselective α-alkylation of esters via 1,6-conjugate addition to para-quinone methides

Funding: We thank the ERC under the European Union's Seventh Framework Programme (FP7/2007-2013)/E.R.C. grant agreement n° 279850, AstraZeneca and EPSRC [EP/M506631/1 (J.N.A.)], Syngenta and the EPSRC Centre for Doctoral Training in Critical Resource Catalysis [CRITICAT, EP/L016419/1 (W.C.H.)], and EPSRC [EP/M508214/1 (C.M.)] for funding. A.D.S. thanks the Royal Society for a Wolfson Research Merit Award. We thank the EPSRC UK National Mass Spectrometry Facility at Swansea University.The isothiourea-catalyzed enantioselective 1,6-conjugate addition of para-nitrophenyl esters to 2,6-disubstituted para-quinone methides is reported. para-Nitrophenoxide, generated in situ from initial N-acylation of the isothiourea by the para-nitrophenyl ester, is proposed to facilitate catalyst turnover in this transformation. A range of para-nitrophenyl ester products can be isolated, or derivatized in situ by addition of benzylamine to give amides, in up to 99% yield. Although low diastereocontrol is observed, the diastereoisomeric ester products are separable and formed with high enantiocontrol (up to 94:6 er).Publisher PDFPeer reviewe

Blurring the boundaries of the Mackintosh room

In this paper we describe a prototype interactive systemsupporting a shared synchronous experience for physical,World Wide Web and virtual reality visitors to anexhibition devoted to the designer and architect C.R.Mackintosh. The system provides awareness betweenvisitors that spans multiple media while also providinglocation- and device-sensitive content to each visitor

Acylative kinetic resolution of alcohols using a recyclable polymer-supported isothiourea catalyst in batch and flow

The authors thank the EPSRC Centre for Doctoral Training in Critical Resource Catalysis (CRITICAT, grant code EP/L016419/1, R.M.N.P.) for funding. Financial support from the EPSRC (EP/K000411/1) is gratefully acknowledged (R.C.). The European Research Council under the European Union’s Seventh Framework Programme (FP7/2007-2013) ERC Grant Agreement No. 279850 is also acknowledged. A.D.S. thanks the Royal Society for a Wolfson Research Merit Award. C.R.-E. and M.A.P. acknowledge the financial support from CERCA Pro-gramme/Generalitat de Catalunya, MINECO (CTQ2015-69136-R, AEI/MINECO/FEDER, UE and Severo Ochoa Excellence Ac-creditation 2014–2018, SEV-2013-0319) and DEC Generalitat de Catalunya (Grant 2014SGR827).A polystyrene-supported isothiourea catalyst, based on the homogeneous catalyst HyperBTM, has been prepared and used for the acylative kinetic resolution of secondary alcohols. A wide range of alcohols, including benzylic, allylic and propargylic alcohols, cycloalkanol derivatives and a 1,2-diol, has been resolved using either propionic or isobutyric anhydride with good to excellent selectivity factors obtained (28 examples, s up to 622). The catalyst can be recovered and reused by a simple filtration and washing sequence, with no special precautions needed. The recyclability of the catalyst was demonstrated (15 cycles) with no significant loss in either activity or selectivity. The recyclable catalyst was also used for the sequential resolution of 10 different alcohols us-ing different anhydrides with no cross-contamination between cycles. Finally, successful application in a continuous flow process demonstrated the first example of an immobilized Lewis base catalyst used for the kinetic resolution of alcohols in flow.PostprintPeer reviewe