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381.
382.
Esmaeilzadeh J. Mardani Z. Moeini K. Carpenter-Warren C. Slawin A. M. Z. Woollins J. D. 《Journal of Structural Chemistry》2022,62(1):S8-S19
Journal of Structural Chemistry - A new zinc(II) complex of 2-(((2-((2-hydroxyethyl)amino)ethyl)imino)methyl)phenol (L), [Zn(Lz)Br2] (1), is prepared and identified by elemental analysis, FTIR and... 相似文献
383.
Podma Pollov Sarmah Bibek Jyoti Borah Alexandra M.Z. Slawin Dipak Kumar Dutta 《Journal of organometallic chemistry》2010,695(24):2603-2608
The dimeric rhodium precursor [Rh(CO)2Cl]2 reacts with quinoline (a) and its three isomeric carboxaldehyde ligands [quinoline-2-carboxaldehyde (b), quinoline-3-carboxaldehyde (c), and quinoline-4-carboxaldehyde (d)] in 1:2 mole ratio to afford complexes of the type cis-[Rh(CO)2Cl(L)] (1a-1d), where L = a-d. The complexes 1a-1d have been characterised by elemental analyses, mass spectrometry, IR and NMR (1H, 13C) spectroscopy together with a single crystal X-ray structure determination of 1c. The X-ray crystal structure of 1c reveals square planar geometry with a weak intermolecular pseudo dimeric structure (Rh?Rh = 3.573 Å). 1a-1d undergo oxidative addition (OA) with different electrophiles such as CH3I, C2H5I and I2 to give Rh(III) complexes of the type [Rh(CO)(COR)Cl(L)I] {R = -CH3 (2a-2d), R = -C2H5 (3a-3d)} and [Rh(CO)Cl(L)I2] (4a-4d) respectively. 1b exhibits facile reactivity with different electrophiles at room temperature (25 °C), while 1a, 1c and 1d show very slow reactivity under similar condition, however, significant reactivity was observed at a temperature ∼40 °C. The complexes 1a-1d show higher catalytic activity for carbonylation of methanol to acetic acid and methyl acetate [Turn Over Frequency (TOF) = 1551-1735 h−1] compared to that of the well known Monsanto’s species [Rh(CO)2I2]− (TOF = 1000 h−1) under the reaction conditions: temperature 130 ± 2 °C, pressure 33 ± 2 bar, 450 rpm and time 1 h. The organometallic residue of 1a-1d was also isolated after the catalytic reaction and found to be active for further run without significant loss of activity. 相似文献
384.
David W. Aldous Alexandra M. Z. Slawin Philip Lightfoot 《Acta Crystallographica. Section C, Structural Chemistry》2010,66(5):m130-m132
The title compound, {(C12H12N2)[V2F6O2(H2O)2]}n, features a novel extended‐chain moiety, [VOF2F2/2(H2O)]n, comprising trans vertex‐connected VOF4(H2O) octahedra. The octahedra themselves show the characteristic distortion due to the off‐centring of the V4+ ion, such that a short terminal V=O bond and an elongated trans V—OH2 bond are present. Hydrogen bonding from the water molecules to terminal F atoms in adjacent chains generates associated chain dimers, which are loosely linked into sheets via additional hydrogen bonding involving the organic moieties. Structural relationships with previously described vanadium oxyfluoride species are briefly discussed. 相似文献
385.
Craig A. Johnston Ross P. Wilkie Helmut Krauss Andrew R. Neal Alexandra M.Z. Slawin Tomas Lebl Nicholas J. Westwood 《Tetrahedron》2018,74(26):3339-3347
The bioactive alkaloid natural product perophoramidine and the related family of compounds known as the communesins have inspired the synthesis community for more than a decade. Many of the elegant approaches have required the synthesis of complex intermediates that have not always reacted in the expected manner. In this study we describe a series of cyclic ether-containing precursors that were prepared during our synthetic studies towards these natural products. Attempts to open the cyclic ether ring and trap the resulting stabilised carbocation with a carbon nucleophile ultimately led to the preparation of a diallyl-substituted all carbon quaternary centre. Subsequent attempts to differentiate between the two allyl groups resulted in a relatively clean transformation to an unexpected compound. Extensive structural characterisation, including small molecule X-ray crystallography, showed that a dearomatisation reaction had occurred. 相似文献
386.
Dr. Adrián Gómez‐Suárez Dr. Yoshihiro Oonishi Dr. Anthony R. Martin Dr. Sai V. C. Vummaleti Dr. David J. Nelson Dr. David B. Cordes Prof. Alexandra M. Z. Slawin Prof. Dr. Luigi Cavallo Prof. Dr. Steven P. Nolan Dr. Albert Poater 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(3):1125-1132
Herein, we present a detailed investigation of the mechanistic aspects of the dual gold‐catalysed hydrophenoxylation of alkynes by both experimental and computational methods. The dissociation of [{Au(NHC)}2(μ‐OH)][BF4] is essential to enter the catalytic cycle, and this step is favoured by the presence of bulky, non‐coordinating counter ions. Moreover, in silico studies confirmed that phenol does not only act as a reactant, but also as a co‐catalyst, lowering the energy barriers of several transition states. A gem‐diaurated species might form during the reaction, but this lies deep within a potential energy well, and is likely to be an “off‐cycle” rather than an “in‐cycle” intermediate. 相似文献
387.
Conformational Dependence of Through‐Space Tellurium–Tellurium Spin–Spin Coupling in Peri‐Substituted Bis(Tellurides)
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Dr. Fergus R. Knight Dr. Louise M. Diamond Dr. Kasun S. Athukorala Arachchige Paula Sanz Camacho Rebecca A. M. Randall Prof. Sharon E. Ashbrook Prof. Michael Bühl Prof. Alexandra M. Z. Slawin Prof. J. Derek Woollins 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(9):3613-3627
Three related series of peri‐substituted bis(tellurides) bearing naphthalene, acenaphthene and acenaphthylene backbones (Nap/Acenap/Aceyl(TeY)2 (Nap=naphthalene‐1,8‐diyl N ; Acenap=acenaphthene‐5,6‐diyl A ; Aceyl=acenaphthylene‐5,6‐diyl Ay ; Y=Ph 1 ; Fp 2 ; Tol 3 ; An‐p 4 ; An‐o 5 ; Tp 6 ; Mes 7 ; Tip 8 ) have been synthesised and their solid‐state structures determined by X‐ray crystallography. Molecular conformations were classified as a function of the two C9‐C‐Te‐C(Y) dihedral angles (θ); in the solid all members adopt AB or CCt configurations, with larger Te(aryl) moieties exclusively imposing the CCt variant. Exceptionally large J(125Te,125Te) spin–spin coupling constants between 3289–3848 Hz were obtained for compounds substituted by bulky Te(aryl) groups, implying these species are locked in a CCt‐type conformation. In contrast, compounds incorporating smaller Te(aryl) moieties are predicted to be rather dynamic in solution and afford much smaller J values (2050–2676 Hz), characteristic of greater populations of AB conformers with lower couplings. This conformational dependence of through‐space coupling is supported by DFT calculations. 相似文献
388.
Dr. David B. Cordes Prof. Alexandra M. Z. Slawin Prof. Dr. Steven P. Nolan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(10):3906-3909
A general methodology for the α‐arylation of ketones using a nickel catalyst has been developed. The new well‐defined [Ni(IPr*)(cin)Cl] ( 1 c ) pre‐catalyst showed great efficiency for this transformation, allowing the coupling of a wide range of ketones, including acetophenone derivatives, with various functionalised aryl chlorides. This cinnamyl‐based Ni–N‐heterocyclic carbene (NHC) complex has demonstrated a different behaviour to previously reported NHC‐Ni catalysts. Preliminary mechanistic studies suggest a Ni0/NiII catalytic cycle to be at play. 相似文献
389.
Danila Gasperini Dr. Alba Collado Dr. Adrián Goméz‐Suárez Dr. David B. Cordes Prof. Dr. Alexandra M. Z. Slawin Prof. Dr. Steven P. Nolan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(14):5403-5412
A new synthetic strategy was devised leading to the formation of complexes, such as [Au(IPr)(CH2COCH3)]. The approach capitalizes on the formation of a decomposition product observed in the course of the synthesis of [Au(IPr)(Cl)]. A library of gold acetonyl complexes containing the most common N‐heterocyclic carbene (NHC) ligands has been synthesized. These acetonyl complexes are good synthons for the preparation of numerous organogold complexes. Moreover, they have proven to be precatalysts in common gold(I)‐catalyzed reactions. 相似文献
390.
Generalization of the Copper to Late‐Transition‐Metal Transmetallation to Carbenes beyond N‐Heterocyclic Carbenes
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Dr. Yannick D. Bidal Orlando Santoro Dr. Mohand Melaimi Dr. David B. Cordes Prof. Alexandra M. Z. Slawin Prof. Guy Bertrand Dr. Catherine S. J. Cazin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(27):9404-9409
Carbene transition‐metal complexes have become a prevalent family of catalysts enabling numerous organic transformations. Their facile synthetic access is a matter of great importance. To this end, the CuI‐NHC transfer methodology has emerged as a powerful alternative presenting attractive advantages over other methods. Herein, we report the remarkable ability of copper to transfer not only NHCs but also other types of carbenes such as abnormal NHCs (aNHCs), cyclic (alkyl)(amino)carbenes (CAACs), and mesoionic carbenes (MICs) to various transition metal precursors. 相似文献