Over a period of many decades, the chemistry of metal–carbon bonds has given rise to an ever-growing field of fundamental research and applied science, merging the reactivity of inorganic complexes with the structural diversity of organic compounds. The contributions in this Thematic Series reflect the broad impact of organometallic compounds in various fields of modern chemical research. These include the tailoring of new ancillary ligands, the investigation of more active and more selective homogeneous catalysts, catalytic transformations in the total synthesis of natural products, the theoretical and kinetic unravelling of reaction mechanisms, and the verification of rare coordination modes. These various facets underline the importance of organometallic chemistry in its own right, but also demonstrate the vital role that research in organometallic chemistry plays as a provider of invaluable tools for other chemistry sub-disciplines.
Graphical Abstract
Figure 1: P,N-ligand frameworks studied in this work.
Scheme 1: Synthesis of N-phosphanylformamidines 2 and 3. Reaction conditions: (i) t-BuLi, THF, −78 °C to rt, ...
Scheme 2: Synthesis of phosphanylformamidines 5 and 7. Reaction conditions: (i) t-BuLi, THF, −78 °C to rt, 1 ...
Scheme 3: Synthesis of complexes [2-M(cod)]X, [3-M(cod)]X, [5-M(cod)]X and [7-M(cod)]X. M = Rh, Ir; X = BF4− ...
Figure 2: Molecular structures of [2a-Rh(cod)]+ (A), [5-Ir(cod)]+ (B), and [7-Rh(cod)]+ (C,D). Anisotropic di...
Figure 3: Coordination of ligands 2a and 5 to Rh(III) and Ir(III) precursors. Yields: [2a-Cp*RhCl]BF4 = 87%, [...
Figure 4: Molecular structures of [2a-Cp*IrI]+ (left) and [5-Cp*IrI]+ (right). Anisotropic displacement ellip...
Figure 5: Formation of palladium complexes of ligands 2a, 5 and 7. (A) Formation of [2a-PdCl2] and [2a-PdCl]2...
Figure 6: Molecular structures of [2a-PdCl2] (left) and [5-Pd(2-Me-allyl)]+ (right). Anisotropic displacement...
Graphical Abstract
Figure 1: Modular concept for manzacidin synthesis based on a Tsuji–Trost coupling of joint intermediate 5.
Scheme 1: General concept for heterocycles synthesis based on a nucleophilic addition and Tsuji–Trost couplin...
Scheme 2: Synthesis of homoallylic alcohol 12 by multi-component reactions.
Scheme 3: Preparation of urea-type cyclization precursor 19.
Scheme 4: Stereodivergent synthesis of 1,3-syn- and anti-tetrahydropyrimidinones [31].
Scheme 5: Stereoselective synthesis of all possible stereoisomers of the manzacidin core amine by asymmetric ...
Scheme 6: Synthesis of the authentic cyclization precursor 5.
Figure 2: X-ray structure of 39.
Scheme 7: Divergent Tsuji–Trost coupling and completion of the synthesis of authentic pyrimidinones 3 and 4.
Graphical Abstract
Scheme 1: Divergent behavior of the palladium and ruthenium-catalyzed Alder–ene reaction.
Scheme 2: Some asymmetric enyne cycloisomerization reactions.
Figure 1: (a) Mechanism for the redox biscycloisomerization reaction. (b) Ruthenium catalyst containing a tet...
Scheme 3: Synthesis of p-anisyl catalyst 1.
Figure 2: Failed sulfinate ester syntheses.
Scheme 4: Using norephedrine-based oxathiazolidine-2-oxide 7 for chiral sulfoxide synthesis.
Scheme 5: (a) General synthetic sequence to access enyne bicycloisomerization substrates (b) Synthesis of 2-c...
Figure 3: Failed bicycloisomerization substrates. Reactions performed at 40 °C for 16 hours with 3 mol % of c...
Scheme 6: Deprotection of [3.1.0] bicycles and X-ray crystal structure of 76.
Scheme 7: ProPhenol-catalyzed addition of zinc acetylide to acetaldehyde for the synthesis of a chiral 1,6-en...
Figure 4: Diastereomeric metal complexes formed after alcohol coordination.
Scheme 8: Curtin–Hammitt scenario of redox bicycloisomerization in acetone.
Graphical Abstract
Scheme 1: Planned Heck reaction of A to compound B and serendipitous discovery of the palladium-catalyzed cyc...
Scheme 2: Synthesis of compounds A (1–6) via methyl 2-siloxycyclopropanecarboxylates D, their alkylation to E...
Scheme 3: Palladium-catalyzed reactions of methyl ketone 1 to tetralin derivative 7 and of isopropyl-substitu...
Scheme 4: Palladium-catalyzed cyclization of diastereomeric cyclopentanone derivatives 3a/3b to products 11a ...
Figure 1: Molecular structure (ORTEP, [14]) of compound 12a (thermal ellipsoids at 50% probability).
Scheme 5: Palladium-catalyzed cyclizations of diastereomeric cyclohexanone derivatives 4a and 4b leading ster...
Figure 2: Molecular structure (ORTEP, [14]) of compound 14a (thermal ellipsoids at 50% probability).
Scheme 6: Palladium-catalyzed cyclizations of cycloheptanone derivatives 5a and 5b leading to products 15a an...
Figure 3: Molecular structure (ORTEP, [14]) of compound 15a (thermal ellipsoids at 50% probability).
Figure 4: Molecular structure (ORTEP [14]) of compound 15b (thermal ellipsoids at 50% probability).
Scheme 7: Palladium-catalyzed cyclization of p-methoxy-substituted aryl iodide 6a/6b to compound 16.
Scheme 8: Typical palladium-catalyzed cyclization of an o-iodoaniline derivative to a tricyclic tertiary alco...
Scheme 9: Proposed transition state (TS) explaining the stereoselective formation of cyclization products.
Scheme 10: Possible mechanism of the reduction of palladium(II) to palladium(0) by triethylamine (additional l...
Graphical Abstract
Scheme 1: Syntheses to Cu(I) complex bearing a NHC ligand.
Scheme 2: Synthesis of Cu(II) terpyridyl complexes.
Scheme 3: Anchoring and refolding of the biohybrid copper complexes.
Figure 1: CD spectra of refolded catalysts 17–19 (red: 17, black: 18, blue: 19).
Figure 2: Temperature-dependent CD spectra of catalyst 17.
Figure 3: MALDI–TOF mass spectra (black: 17, red: FhuAΔCVFtev).
Graphical Abstract
Scheme 1: Imine formation and isomerization reactions from NH carbene complexes Cr(CO)5(E-2) (a) [27], Cr(CO)5(E/Z...
Scheme 2: Synthesis of W(CO)5(E-2) from W(CO)5(1Et) [20,21] and aminoferrocene [40,41] with concomitant formation of E-1,2-...
Scheme 3: Reaction pathways 1a/1b (migration–elimination) and 2a/2b (elimination–migration) for the formation...
Scheme 4: Reaction pathways 3a/3b/3c (CO dissociation) for the formation of imine E-3 from W(CO)5(E-2).
Figure 1: DFT calculated oxidative addition/pseudorotation/reductive elimination pathway 3c from W(CO)4(E-2) ...
Figure 2: DFT calculated geometries of the two hydrido intermediates cis(N,H)-W(CO)4(H)(Z-15) and cis(C,H)-W(...
Scheme 5: Proposed reaction sequence from W(CO)5(E-2) to W(CO)5(PPh3) in the presence of triphenylphosphane.
Graphical Abstract
Scheme 1: Influencing catalyst stability, olefin coordination and chain-transfer reactions by hemilabile dono...
Scheme 2: Synthesis of ligands L1–L8 and chromium complexes 1–8.
Figure 1: Solid-state molecular structures of selected complexes 4, 7 and 8 (left, middle and right, respecti...
Figure 2: a) Calculated structures of cationic chromium complexes. Chromium–donor distances [Å]: 3a+ [2.21], ...
Figure 3: Comparison of GPC traces of polyethylene produced by 1/PMAO and 8/PMAO respectively (entries 1 and ...
Graphical Abstract
Figure 1: The four coordination geometries for d10 polyene-ML2 complexes along with their hapto numbers and e...
Figure 2: The important valence orbitals of a d10 ML2 group, 5–7, along with the computed structures of Pt(PH3...
Figure 3: The empty degenerate set of π orbitals in the cyclopropenium cation is shown on the left side. On t...
Figure 4: Two unoccupied MOs for Cp+ are shown on the left side. The two stationary points for Cp–Pt(dpe)+ ar...
Figure 5: The half-filled degenerate π orbitals in cyclobutadiene. The computed ground state (15) and transit...
Figure 6: The ground and transition state for ring whizzing in F6C6–Pt(dpe), 17 and 20, respectively. The dom...
Figure 7: The LUMO, 23, and HOMO, 27, in 6-radialene. The optimized η2 ground states are shown in 24 and 25 w...
Figure 8: Two representations for the half-filled e2u set of π orbitals in cyclooctatetraene.
Figure 9: The stationary points found on the potential energy surface of C8F8–Pt(dpe). For clarity the groups...
Figure 10: The two important bonding interactions for transition state 31 are drawn in 33 and 34.
Figure 11: Three other coordination geometries that did not lead to new stationary points are shown in 35–37.
Figure 12: The LUMO and LUMO+1 shown in 38 and 39, respectively. The four stationary points found for pentalen...
Figure 13: The LUMO of the phenalenium cation is given in 44. The structures of the three stationary points fo...
Figure 14: A top view of two stationary points found for F8C10–Pt(dpe); 48 is the ground state and 50, represe...
Figure 15: At top view of the η4, 52, and η4, 54, transition states along with the η2, 53, intermediate.
Graphical Abstract
Figure 1: Synthetic overview of “NU-BIPHEP(O)s”. A) Rhodium catalyzed double [2 + 2 + 2] cycloaddition. B) Ac...
Figure 2: Investigation of 3,5-dichlorobenzoyl modified tetrahydrobiisoindole “NU-BIPHEP(O)” 3. A) Three sign...
Figure 3: Investigation of “NU-BIPHEP(O)” 1b. A) Solid-state structure determined by X-ray crystallography. H...
Figure 4: Enantioselective DHPLC investigation of tetrahydrobiisoindole “NU-BIPHEP(O)” 3. A) Elution profiles...
Graphical Abstract
Scheme 1: Synthesis of the monomethylpalladium(II) complexes 9–11 (in DCM) and 12 (in CH3CN).
Figure 1: Possible isomers.
Figure 2: ORTEP [39] style plot of complex 9 in the solid state. Thermal ellipsoids are given at the 50% probabil...
Figure 3: ORTEP [39] style plot of complex 12 in the solid state. Thermal ellipsoids are drawn at the 50% probabi...
Scheme 2: Synthesis of complex 13.
Figure 4: ORTEP [39] style plot of complex 13 in the solid state. Thermal ellipsoids are drawn at the 50% probabi...
Scheme 3: Possible pathways of methyl trifluoroacetate formation starting from complex 13.
Scheme 4: Synthesis of complex 14 by conversion of complex 13 with iodobenzene bistrifluoroacetate.
Scheme 5: Synthesis of the [((pym)^(NHC-R))PdII(CH3)2] complex 15.
Graphical Abstract
Scheme 1: Disfavored mononuclear pathway and favored dinuclear pathway in the CuAAC click reaction, according...
Figure 1: Ball-and-stick model [42,43] of a single crystal X-ray structure of hexafluorophosphate salt 1b (CCDC 1472...
Scheme 2: Synthesis of dinuclear copper complex 2.
Figure 2: Time-conversion-diagram of the CuAAC reaction of benzyl azide with either phenylacetylene or ethyl ...
Graphical Abstract
Figure 1: Selected M→B coordination modes 1–5 [6-10] and Hofmann’s Rucaphos complex 6 [11].
Scheme 1: Synthesis of diphosphinoborane CyDPBPh and complex 9.
Figure 2: Thermal ellipsoid plots of complex 9 at the 50% probability level. H atoms and one molecule of hexa...
Graphical Abstract
Figure 1: Left: resonance hybrid of the dipyrido carbenes dipiy and dipiytBu. Right: two canonical forms of t...
Scheme 1: Preparation of the 13CO substituted rhodium complexes 2 bearing the dipyrido-annelated carbenes dip...
Figure 2: 13C NMR spectra (carbonyl region, 125 MHz) of the reaction of 1a with 13CO under variable pressure ...
Scheme 2: Proposed mechanism for the preferred exchange of the cis-CO ligand based on DFT-calculations (BP86 ...
Figure 3: IR scale (cm−1) to determine the overall electron-donor capacity of various N-heterocyclic carbenes...
Figure 4: Highest occupied molecular orbitals for the dipyrido-annelated carbene dipiy. The σ-type carbene lo...
Figure 5: Molecular orbitals of the Rh complexes II-Rh, III-Rh and 2a that show ligand-metal π-bonds.
Graphical Abstract
Figure 1: Thienyl-bridged oligophenothiazines as topological hybrids of (oligo)phenothiazines and 2,5-di(hete...
Scheme 1: One-pot bromine-lithium-exchange-borylation-Suzuki (BLEBS) synthesis of 7-bromo-substituted phenoth...
Scheme 2: Pseudo five-component Sonogashira-Glaser-cyclization synthesis of thienyl-bridged oligophenothiazin...
Figure 2: Cyclic voltammograms of compounds 3 (recorded in CH2Cl2, T = 293 K, electrolyte n-Bu4N+PF6−, Pt wor...
Figure 3: UV–vis (solid lines) and fluorescence spectra (dashed lines) of the thienyl-bridged oligophenothiaz...
Figure 4: DFT-calculated minimum conformer of the 2,5-bis(terphenothiazinyl)thiophene 3c (calculated with the...
Figure 5: Relevant Kohn–Sham FMOs contributing to the S1 states that are assigned to the longest wavelengths ...