Bryan M. Gatehouse

Bio: Bryan M. Gatehouse is an academic researcher from Monash University, Clayton campus. The author has contributed to research in topics: Crystal structure & Denticity. The author has an hindex of 21, co-authored 92 publications receiving 1346 citations.

Organolanthanoids. XI: The crystal and molecular structures of two tris(η5-cyclopentadienyl)(pyridine)lanthanoid(III) compounds

Abstract: The crystal structures of tris (η5-cyclopentadienyl) (pyridine) samarium(III), monoclinic, space group P21/c, a 10.906(4), b 8.636(2), c 17.825(3) A, β 96.44(2)o, Z 4, R 0.027 and Rw 0.032 for 3619 'observed' reflections, and tris (η5-cyclopentadienyl)(pyridine)neodymium(III), monoclinic, space group P21 / c, a 14-206(4), b 8.619(2), c 15.190(7) A, β 107.38(2)o, Z 4, R 0.035 and R, 0.039 for 2677 'observed' reflections have been determined. Both compounds have pseudotetrahedral geometry with a coordination number of 10 for the lanthanoid metal but there is a difference in the coordination of pyridine and in unit cell packing between the two structures.

The autoxidation of a chromium (II) porphyrin: synthesis and structural characterisation by X-ray crystallography of αβγδ-tetraphenyl-porphinato-oxochromium(IV)

Abstract: The reaction of dioxygen with αβγδ-tetraphenyl-porphinatochromium (II) in toluene proceeds in two stages; a µ-oxo-chromium(III) intermediate is formed initially and this then further reacts with dioxygen to give the title complex, the structure of which has been determined by X-ray crystallography.

Coordination chemistry of methylmercury(II). Complexes of aromatic nitrogen donor tripod ligands involving new coordination geometries for methylmercury(II)

Abstract: Complexes [MeHgL]N03 {L = diphenyl(2-pyridy1)methane (pyCHPh2), bis(2-pyridy1)phenylmethane [(py)2CHPh], and the tripod ligands tris(2-pyridy1)carbinol [(py)3COH] and bis(2-pyridyl)(N-methyl-2-imidazolyl)carbinol [(py)2(NMeIm)COH]} are obtained from addition reactions in acetone. The ligand (py)2CHPh is formed on reaction of (2-benzylpyridy1)lithium with 2-bromopyridine. 1H NMR spectra indicate that (py)2CHPh and (py)2(N-Me1m)COH are present as bidentates in methanol solutions of their complexes, with the latter coordinated via the imidazolyl ring and one pyridyl ring. Spectra are consistent with the presence of weak pi interactions between mercury and phenyl rings in the (py)CHPh2 and (py)2CHPh complexes and the uncoordinated pyridyl ring in the (py)2(N-Me1m)COH complex. In complexes [MeHgL]N03 (L = (py)3OH, (py)3CH) the ligands are present as tridentates in methanol. Crystalline [MeHgL]NO3 [L = (py)3OH, (py)2(N-MeIm)COH] have the tripod ligands coordinating as tridentates, with irregular coordination geometries based on a dominant C-Hg-N’ moiety [Hg-N’ = 2.28 (1) A, C-Hg-N’ = 150(1)O ((py)3COH) and 2.13(1) A, 170(0) ((py)2(N-MeIm)COH)] with weaker Hg-N,N” bonds [2.45(l), 2.53(1) ((py)3OH) and 2.66(l), 2.71(1) A ((py)2(N-MeIm)COH)]. For [MeHg((py)2(N-MeIm)COH)] the coordination geometry resembles a trigonal bipyramid lacking one equatorial donor and with axial direction C-Hg-N’.

Organoamido‐ and aryloxo‐lanthanoids. XIII [1]. Organometallic compounds of the lanthanoids. CV [2]. New Lanthanoid(III) Complexes with Pyrazolate Ligands

Abstract: The complexes Er(Me2pz)3(thf) and Ln(Ph2pz)3(thf)n (Ln = Sc, Y, Gd, Er, n = 2; Ln = Lu, n = 3) (Me2pz− = 3,5-dimethylpyrazolate, thf = tetrahydrofuran, Ph2pz− = 3,5-diphenylpyrazolate) have been prepared by reaction of the lanthanoid metal with bis(pentafluorophenyl)mercury and the pyrazole in thf. The Ln(Ph2pz)3(thf)2 complexes are considered to be eight coordinate with three η2-Ph2pz ligands. Other lanthanoid pyrazolate complexes, Y(pz)3(thf)2, La(Me2pz)3(thf), Cp2Ln(Me2pz)(thf)n (Ln = Y, Lu, n = 0; Ln = Lu, n = 1), (C5Me5)2Y(pz)(thf), (C5Me5)2Y(Mepz)(thf), (C5Me5)2Y(Me2pz)(thf)2 (pz− = pyrazolate, Mepz− = 3-methylpyrazolate, Cp = cyclopentadienyl) have been synthesized by reaction of LnCl3, Cp2LnCl, or (C5Me5)2LnCl with the appropriate sodium pyrazolate in thf. The structure of Ln(Me2pz)3(thf) (Ln = La or Er) is considered to be a symmetrical dimer with four chelating and two bridging Me2pz groups, and two bridging thf ligands, whereas the cyclopentadienyl complexes are most likely dimers with bridging pyrazolate groups, and lattice thf of solvation. Organoamido- und Aryloxo-Lanthanoidverbindungen. XIII [1]. Metallorganische Verbindungen der Lanthanoide. CV [2]. Neue Lanthanoid(III) Komplexe mit Pyrazolat-Liganden Die Komplexe Er(Me2pz)3(thf) und Ln(Ph2pz)3(thf)n (Ln = Sc, Y, Gd, Er, n = 2; Ln = Lu, n = 3) (Me2pz− = 3,5-Dimethylpyrazolat, thf = Tetrahydrofuran, Ph2pz− = 3,5-Diphenylpyrazolat) wurden durch Reaktion der Lanthanoid-Metalle mit Bis(pentafluorophenyl)quecksilber und den entsprechenden Pyrazolderivaten in thf dargestellt. In den Komplexen Ln(Ph2pz)3(thf)2 besetzen drei η2-Ph2pz Liganden sechs der acht Koordinationsstellen am Ln. Die Pyrazolatkomplexe, Y(pz)3(thf)2, La(Me2pz)3(thf), Cp2Ln(Me2pz)(thf)n (Ln = Y, Lu, n = 0; Ln = Lu, n = 1), (C5Me5)2Y(pz)(thf), (C5Me5)2Y(Mepz)(thf), (C5Me5)2Y(Me2pz)(thf)2 (pz− = Pyrazolat, Mepz− = 3-Methylpyrazolat, Cp = Cyclopentadienyl) wurden durch Reaktion von LnCl3, Cp2LnCl oder (C5Me5)2LnCl mit den entsprechenden Natriumpyrazolaten in thf erhalten. Die Komplexe Ln(Me2pz)3(thf) (Ln = La, Er) sind symmetrische Dimere mit vier chelatisierenden und zwei verbruckenden Me2pz Gruppen neben zwei verbruckenden thf Liganden. Die Cyclopentadienylkomplexe liegen als Dimere mit verbruckenden Pyrazolatgruppen und eingelagertem thf vor.

Organometallic compounds containing a guanidinium group. Phenylmercury(II) derivatives of creatine and creatinine

Abstract: Phenylmercury(II) replaces a proton of creatine, H2NC+(NH2)NMeCH2C02-, in basic solution to form the zwitterionic complex PhHgNHC+(NH2)NMeCH2CO2-. Creatine and creatinine (C4H7N30) react with PhHg((OH)N03)I/2 in aqueous ethanol to form a 2:l complex [(PhHg)2(C4H6N30][N03] which exists in two crystalline forms. Creatinine forms a 1:l complex [PhHg(C4H7N30)][N03].1/2H20 at pH 1.4 on reaction with PhHg((OH)N03)l/2 in the presence of nitric acid. The 1:l and 2:l complexes may be interconverted. Creatinine hydronitrate, [H2NCNMeCH2CONH][NO3], and the PhHg(II) complexes of creatinine have similar infrared (including deuterated derivatives) and 1H NMR spectra, consistent with retention of the creatinine ring and presence of a guanidinium group in the complexes. An X-ray structural analysis of one crystalline form of the 2:l complex shows bonding of PhHg(II) groups to the exocyclic and ring nitrogens of creatinine to form the cation [PhHgNHCNMeCH2CONHgPh]+.

Palladium-catalyzed cross-coupling reactions in total synthesis.

Abstract: In studying the evolution of organic chemistry and grasping its essence, one comes quickly to the conclusion that no other type of reaction plays as large a role in shaping this domain of science than carbon-carbon bond-forming reactions. The Grignard, Diels-Alder, and Wittig reactions are but three prominent examples of such processes, and are among those which have undeniably exercised decisive roles in the last century in the emergence of chemical synthesis as we know it today. In the last quarter of the 20th century, a new family of carbon-carbon bond-forming reactions based on transition-metal catalysts evolved as powerful tools in synthesis. Among them, the palladium-catalyzed cross-coupling reactions are the most prominent. In this Review, highlights of a number of selected syntheses are discussed. The examples chosen demonstrate the enormous power of these processes in the art of total synthesis and underscore their future potential in chemical synthesis.

Cascade reactions in total synthesis.

Abstract: The design and implementation of cascade reactions is a challenging facet of organic chemistry, yet one that can impart striking novelty, elegance, and efficiency to synthetic strategies. The application of cascade reactions to natural products synthesis represents a particularly demanding task, but the results can be both stunning and instructive. This Review highlights selected examples of cascade reactions in total synthesis, with particular emphasis on recent applications therein. The examples discussed herein illustrate the power of these processes in the construction of complex molecules and underscore their future potential in chemical synthesis.

The Diels--Alder reaction in total synthesis.

Abstract: The Diels-Alder reaction has both enabled and shaped the art and science of total synthesis over the last few decades to an extent which, arguably, has yet to be eclipsed by any other transformation in the current synthetic repertoire. With myriad applications of this magnificent pericyclic reaction, often as a crucial element in elegant and programmed cascade sequences facilitating complex molecule construction, the Diels-Alder cycloaddition has afforded numerous and unparalleled solutions to a diverse range of synthetic puzzles provided by nature in the form of natural products. In celebration of the 100th anniversary of Alder's birth, selected examples of the awesome power of the reaction he helped to discover are discussed in this review in the context of total synthesis to illustrate its overall versatility and underscore its vast potential which has yet to be fully realized.