New Protocol for the Synthesis of S-Thioesters from Benzylic, Allylic and Tertiary Alcohols with Thioacetic Acid

A new one-pot solvent-less reaction to convert benzylic, allylic, ferrocenyl or tertiary alcohols into S-thioesters, bench-stable and less odorous precursors of the corresponding thiols, which is based on reactions in neat thioacetic acid in the presence of tetrafluoroboric acid, is presented. Reaction monitoring by NMR and GC of the benzyl alcohol conversion indicated the intermediate formation of benzyl acetate and benzyl thionoacetate (PhCH2 OC(S)CH3 ) prior to the slower conversion to the final S-benzyl thioacetate product. Increasing the HBF4 concentration enhanced the reaction rate, giving good to excellent yield (up to 99 %) for a large scope of alcohols. Control experiments, with support of DFT calculations, have revealed a thermodynamically favorable, though requiring HBF4 -activation, disproportionation of CH3 C(O)SH to CH3 C(O)OH and CH3 C(S)SH, the latter immediately decomposing to H2 S and (MeC)4 S6 but also generating the hitherto unreported [MeC(O)C(Me)S]2 (μ-S)2 . Kinetic investigations demonstrated that the rate of benzyl alcohol conversion is second-order in [PhCH2 OH] and second order in [HBF4 ], while the rate of conversion of the benzyl acetate intermediate to S-benzyl thioacetate is second order in [PhCOOMe] and fourth order in [HBF4 ]. The DFT calculations rationalize the need to two alcohol molecules and two protons to generate the reactive benzyl cation.

Acetate exchange mechanism on a Zr12 oxo hydroxo cluster: relevance for reshaping Zr-carboxylate coordination adaptable networks

The kinetics and mechanism of the acetate ligand exchange with free acetic acid in [Zr6O4(OH)4(O2CCH3)12]2, used as a molecular model of crosslink migration in [Zr6O4(OH)4(carboxylate)12-n(OH)n]-based coordination adaptable networks with vitrimer-like properties, has been thoroughly investigated by dynamic 1H NMR and DFT calculations. The compound maintains its C2h-symmetric Zr12 structure in CD2Cl2 and C6D6, while it splits into its Zr6 subunits in CD3OD and D2O. In the Zr12 structure, the topologically different acetates (3 chelating, 6 belt-bridging, 2 intercluster-bridging and 1 inner-face-bridging) of the Zr6 subunits behave differently in the presence of free CH3COOH: very fast exchange for the chelating (coalesced resonance at room temperature), slower exchange for the belt-bridging (line broadening upon warming), no observable exchange up to 65 °C (by EXSY NMR) for the intercluster- and inner-face-bridging. The rates of the first two exchange processes have zero-order dependence on [CH3COOH]. Variable-temperature line broadening studies yielded ΔH‡ = 15.0 ± 0.4 kcal mol-1, ΔS‡ = 8 ± 1 cal mol-1 K-1 (-30 to +25 °C range in CD2Cl2) for the chelating acetates and ΔH‡ = 22.7 ± 1.6, 22.9 ± 2.1 and 20.6 ± 1.0 kcal mol-1 and ΔS‡ = 13 ± 5, 14 ± 6 and 9 ± 3 cal mol-1 K-1, respectively (+25 to +70 °C range in C6D6), for three distinct resonances of magnetically inequivalent belt-bridging acetates. With support of DFT calculations, these results point to an operationally associative mechanism involving a rate-determining partial dissociation to monodentate acetate, followed by rapid acid coordination and proton transfer. The cluster μ3-OH ligands accelerate the exchange processes through H-bonding stabilization of the coordinatively unsaturated intermediate. The lower exchange barrier for the chelated vs. bridging acetates is associated to the release of ring strain. The results presented in this investigation may help the interpretation of carboxylate exchange phenomena in other systems and the design of new carboxylate-based materials.

A mononuclear cobalt(III) carboxylate complex with a fully O-based coordination sphere: CoIII-O bond homolysis and controlled radical polymerisation from [Co(acac)2(O2CPh)]

The addition of benzoyl peroxide to [Co^II(acac)₂] in a 1 : 2 ratio selectively produces [Co^III(acac)₂(O₂CPh)], a diamagnetic (NMR) mononuclear Co^III complex with an octahedral (X-ray diffraction) coordination geometry. It is the first reported mononuclear Co^III derivative with a chelated monocarboxylate ligand and an entirely O-based coordination sphere. The compound degrades in solution quite slowly by homolytic Co^III-O₂CPh bond cleavage upon warming above 40 °C to produce benzoate radicals and can serve as a unimolecular thermal initiator for the well-controlled radical polymerisation of vinyl acetate. Addition of ligands (L = py, NEt₃) induces benzoate chelate ring opening and formation of both cis and trans isomers of [Co^III(acac)₂(O₂CPh)(L)] for L = py under kinetic control, then converting quantitatively to the cis isomer, whereas the reaction is less selective and equilibrated for L = NEt₃. The py addition strengthens the Co^III-O₂CPh bond and lowers the initiator efficiency in radical polymerisation, whereas the NEt₃ addition results in benzoate radical quenching by a redox process. In addition to clarifying the mechanism of the radical polymerisation redox initiation by peroxides and rationalizing the quite low efficiency factor for the previously reported [Co^II(acac)₂]/peroxide-initiated organometallic-mediated radical polymerisation (OMRP) of vinyl acetate, this investigation provides relevant information on the Co^III-O homolytic bond cleavage process.

Synthesis and crystal structure of [(Sp )-(2-phenylferrocenyl)methyl]trimethylammonium iodide dichloromethane monosolvate

The packing of the title disubstituted ferrocene derivative is stabilized by weak C—H⋯X (X = I, Cl), C—H⋯π(Cp) and C—Cl⋯π(phen­yl) inter­actions, building a three-dimensional network. The cation has planar chirality with S_p(Fc) absolute configuration. The structure of the title compound is compared with related disubstituted (tri­meth­ylammonio)­methyl ferrocenes.

As a follow-up to our research on the chemistry of disubstituted ferrocene derivatives, the synthesis and the structure of the title compound, [Fe(C₅H₅)(C₁₅H₁₉N)]I·CH₂Cl₂, is described. The cation mol­ecule is built up from a ferrocene disubstituted by a tri­methyl­ammonium methyl group and a phenyl ring. The asymmetric unit contains the iodide to equilibrate the charge and a disordered di­chloro­methane solvate. The disordered model results from a roughly statistical exchange (0.6/0.4) between one Cl and one H. The packing of the structure is stabilized by weak C—H⋯X (X = I, Cl), C—H⋯π(Cp) and C—Cl⋯π(phen­yl) inter­actions, building a three-dimensional network. The cation has planar chirality with S_p(Fc) absolute configuration. The structure of the title compound is compared with related disubstituted (tri­meth­ylammonio)­methyl ferrocenes.

Iodine-promoted insertion of the oxygen atom from water in η4-vinylketene[Fe(CO)3] complexes

Iodine promotes the in situ formation of iron(II) species from η⁴-vinylketene[Fe(CO)₃] (3a-h) as a key intermediate for the synthesis of 2(5H)-furanones (4a-h) by a sequential water-insertion/carbon-oxygen coupling under mild reaction conditions. Compounds 4a-h were obtained in good to excellent yields. A possible reaction pathway was also proposed by DFT calculations. This methodology can be extended to the synthesis of (5H)-pyrrol-2-ones using anilines, with moderate yields and a few limitations.

Interrupted Intramolecular Hydroaminomethylation of N-Protected-2-vinyl Anilines: Novel Access to 3-Substitued Indoles or Indoline-2-ols

A new synthetic alternative to the synthesis of 3-methyl indoles and 3-methyl indoline-2-ols with an excellent atomic economy is presented in this study. It is demonstrated that the intramolecular interrupted hydroaminomethylation (HAM) reaction is a powerful tool for the formation of these compounds, which exhibit wide-ranging biological activity. Several N-Protected-2-vinyl anilines were synthesized and involved in the reaction producing the corresponding 3-methylindole or 3-methyl indoline-2-ol depending on the nature of the N-protecting groups.

Replacement of Volatile Acetic Acid by Solid SiO2@COOH Silica (Nano)Beads for (Ep)Oxidation Using Mn and Fe Complexes Containing BPMEN Ligand

Mn and Fe BPMEN complexes showed excellent reactivity in catalytic oxidation with an excess of co-reagent (CH3COOH). In the straight line of a cleaner catalytic system, volatile acetic acid was replaced by SiO2 (nano)particles with two different sizes to which pending carboxylic functions were added (SiO2@COOH). The SiO2@COOH beads were obtained by the functionalization of SiO2 with pending nitrile functions (SiO2@CN) followed by CN hydrolysis. All complexes and silica beads were characterized by NMR, infrared, DLS, TEM, X-ray diffraction. The replacement of CH3COOH by SiO2@COOH (100 times less on molar ratio) has been evaluated for (ep)oxidation on several substrates (cyclooctene, cyclohexene, cyclohexanol) and discussed in terms of activity and green metrics.

Synthesis and crystallographic studies of 2-(di-phenyl-phosphino-thio-yl)-2-(3-oxobut-1-en-yl)ferrocene

The title mol­ecule is built up from a ferrocene unit disubstituted by an S-protected di­phenyl­phosphine group and by a methyl­vinyl­ketone chain. In the crystal, weak C—H⋯O and C—H⋯S inter­actions build a two-dimensional network.

As a follow-up to our research on the chemistry of disubstituted ferrocene derivatives, the synthesis and the structure of the title compound, 2-(di­phenyl­phosphino­thio­yl)-2-(3-oxobut-1-en-yl)ferrocene, [Fe(C₅H₅)(C₂₁H₁₈OPS)], are described. The mol­ecule is built up from a ferrocene unit disubstituted by an S-protected di­phenyl­phosphine group and by a methyl­vinyl­ketone chain. The crystal structure features weak C—H⋯O and C—H⋯S inter­actions, which build a two-dimensional network. This structure is compared to that of the related disubstituted di­phenyl­phosphino ferrocene.

Amphiphilic polymeric nanoreactors containing Rh(i)–NHC complexes for the aqueous biphasic hydrogenation of alkenes

A rhodium(i) complex bearing a monodentate N-heterocyclic carbene ligand has been confined into the core of amphiphilic core-crosslinked micelles (CCMs).

A new P,S-coordinating ferrocenyl ligand: synthesis of a precursor and its coordination compounds with PdII and PtII. Corrigendum

In the paper by Mouas Toma et al. [Acta Cryst. (2014), C70, 460–464], there was an error in the name of the first author.

Erratum: rac-{[2-(Diphenyl-thio-phosphor-yl)ferrocen-yl]meth-yl}dimethyl-ammonium diphenyl-dithio-phosphinate. Corrigendum

Corrigendum to Acta Cryst. (2012), E68, m381–m382.

In the paper by Mouas et al. [Acta Cryst. (2012), E68, m381–m382], there was an error in the name of the first author.

Crystal structure of (R)-5-[(R)-3-(4-chloro-phen-yl)-5-methyl-4,5-di-hydro-isoxazol-5-yl]-2-methyl-cyclo-hex-2-enone

The title compound is a pure diastereoisomer built up from a central five-membered di­hydro­isoxazole ring substituted in the 3 and 5 positions by a p-chloro­phenyl group and a cyclo­hex-2-enone ring. The cyclo­hex-2-one and the isoxazoline rings both exhibit an envelope conformation. The crystal packing features C—H⋯O, C—H⋯N and C—H⋯π inter­actions.

The title compound, C₁₇H₁₈ClNO₂, was prepared and isolated as a pure diastereoisomer, using column chromatography followed by a succession of fractional crystallizations. Its exact structure was fully identified via¹H NMR and confirmed by X-ray diffraction. It is built up from a central five-membered di­hydro­isoxazole ring to which a p-chloro­phenyl group and a cyclo­hex-2-enone ring are attached in the 3 and 5 positions. The cyclo­hex-2-one and isoxazoline rings each exhibit an envelope conformation. The crystal packing features C—H⋯O, C—H⋯N and C—H⋯π inter­actions, which generate a three-dimensional network.

Synthesis of S-Alkyl Phosphinocarbodithioates with Switch between P(III) and P(V) Derivatives

Simple and effective synthetic pathways are described to prepare compounds R₂P(X)C(S)SCH(Me)Ph with the P atom either in the oxidation state V [R/X = t-Bu/O (6), Ph/S, (7), t-Bu/S (8), t-Bu/Se (9)] or III [R/X = Ph/BH₃ (4), t-Bu/BH₃ (5), t-Bu/lone pair (10)]. Compound 9 is the first example of carbodithioate ester with a P = Se group, and for the first time, a phosphinocarboditioate with a free phosphine function (compound 10) is described. Stabilization of the latter crucially depends on the steric protection by the t-Bu groups since an analogous derivative with R = Ph is observable but too unstable for isolation. Compound 10 can be reversibly protonated to yield the [t-Bu₂PHC(S)SCH(Me)Ph]⁺ cation (10-H⁺), which was isolated as a BF₄^- salt. A few interconversion processes resulting in the facile addition/removal or exchange of the X group in this family of compounds are also described. The oxidation state of the phosphorus atom and the nature of an electron-withdrawing group have a significant impact on the spectral properties.

Crystal structure of penta-carbon-yl(2,2-di-fluoro-propane-thio-ato-κS)manganese(I)

The synthesis and crystal structure of an unexpected CH₃CF₂C(O)SMn(CO)₅ compound are described.

The title compound, [Mn{SC(O)CF₂CH₃}(CO)₅], has been isolated as a by-product during the reaction of K[Mn(CO)₅] with CH₃CF₂COCl. It is built up from a di­fluoro­methyl­propane­thio­ate bonded to an Mn(CO)₅ moiety through the S atom. The Mn atom has an almost perfect octa­hedral coordination sphere. It is one of the rare examples of compounds containing the (CO)₅MnS—C fragment. In the crystal, the methyl group occupies a pocket surrounded by the O atoms of three carbonyl groups of the Mn(CO)₅ moiety; however, the H⋯O distances are rather long. These inter­actions lead to the formation of layers lying parallel to (101), which enclose R₄⁴(15) and R₄⁴(16) ring motifs. The CF₂ group is disordered over two sets of sites with occupancies of 0.849 (3) and 0.151 (3).

New polysubstituted monoterpenic thiazolidinones: synthesis, spectroscopic and crystal structure studies

The synthesis of three new polysubstituted monoterpenic thiazolidin-4-ones, namely (Z)-3-methyl-2-{(E)-[(1R,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ylidene]hydrazinylidene}thiazolidin-4-one, C14H21N3OS (2), (2Z,5Z)-5-[(dimethylamino)methylidene]-2-{(E)-[(1R,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ylidene]hydrazinylidene}thiazolidin-4-one, C16H24N4OS (3), and (2Z,5Z)-5-[(dimethylamino)methylidene]-3-methyl-2-{(E)-[(1R,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ylidene]hydrazinylidene}thiazolidin-4-one, C17H26N4OS (4), is reported, starting from the corresponding thiosemicarbazones obtained from naturally occurring (R)-camphor. All the newly obtained thiazolidin-4-ones have been fully characterized by HRMS and 1H and 13C (1D and 2D) NMR spectroscopy. Two of them, i.e. 2 and 3, were identified by single-crystal X-ray crystallography, confirming the synthetic pathway and the spectroscopic analyses. In 3, there are two roughly identical molecules within the asymmetric unit with the same absolute configuration. These two molecules are linked through N—H...O hydrogen bonds, building an R 2 2(8) graph-set motif.

Crystal structure of 2-isopropyl-4-meth-oxy-5-methyl-phenyl 4-methyl-benzene-sulfonate

The title compound, C18H22O4S, an hemisynthetic product, was obtained by the tosyl-ation reaction of the naturally occurring meroterpene p-meth-oxy-thymol. The mol-ecule comprises a tetra-substitued phenyl ring linked to a toluene-sulfonate through one of its O atoms. In the crystal, C-H⋯O and C-H⋯π inter-actions link the mol-ecules, forming a three-dimensional network.

Triangles and Squares for a Unique Molecular Crystal Structure: Unsupported Two-Coordinate Lithium Cations and CC Agostic Interactions in Cyclopropyllithium Derivatives

Understanding and controlling the aggregation state is germane to alkyllithium chemistry. Lewis base-free alkyllithium compounds normally form tetrahedral tetramers or octahedral hexamers in the solid state with the lithium cations being three-coordinate. We report that the unsupported cyclopropyl derivative 1-(trimethylsilyl)cyclopropyllithium [{μ-c-C(SiMe₃ )C₂ H₄ }Li]₄ (1), synthesized by the reduction of 1-(phenylthio)-1-(trimethylsilyl)cyclopropane, crystallizes as a tetramer in the space group I-4 with the two-coordinate lithium atoms forming a square. CC agostic interactions complete the coordination sphere around each lithium. The aggregate is preserved in hydrocarbon solution. Furthermore, CC agostic interactions compete intra- and intermolecularly with Lewis base donation as in the unsaturated dimer of 1-(phenylthio)cyclopropyllithium [Li(thf)₂ {μ-c-C(SPh)C₂ H₄ }₂ Li (thf)] (3) which is also fully characterized.

The crystal structure of a new ferrocenyl P,N ligand: 1-[(2,2-di-methyl-hydrazin-1-yl-idene)meth-yl]-1'-(di-phenyl-phospho-rothio-yl)ferrocene

The asymmetric unit of the title compound contains two independent mol­ecules with very similar conformations. Each mol­ecule is built up from a ferrocene unit substituted in the 1 and 1′ positions by a protected sulfur di­phenyl­phosphine and by a di­methyl­hydrazine fragment.

The asymmetric unit of the title compound, [Fe(C₈H₁₁N₂)(C₁₇H₁₄PS)], contains two independent mol­ecules (A and B) with very similar conformations. Each mol­ecule is built up from a ferrocene unit substituted in the 1 and 1′ positions by a protected sulfur di­phenyl­phosphine and by a di­methyl­hydrazine, –C(H)=N—N(CH₃)₂, fragment. The two independent mol­ecules are linked by a C—H⋯N hydrogen bond. In the crystal, the A–B dimer is linked by a pair of C—H⋯S hydrogen bonds, forming a centrosymmetric four-mol­ecule arrangement. These units are linked by C—H⋯π inter­actions, forming a supra­molecular three-dimensional structure.

Synthesis and Characterization of the Most Active Copper ATRP Catalyst Based on Tris[(4-dimethylaminopyridyl)methyl]amine

The tris[(4-dimethylaminopyridyl)methyl]amine (TPMA^NMe2) as a ligand for copper-catalyzed atom transfer radical polymerization (ATRP) is reported. In solution, the [Cu^I(TPMA^NMe2)Br] complex shows fluxionality by variable-temperature NMR, indicating rapid ligand exchange. In the solid state, the [Cu^II(TPMA^NMe2)Br][Br] complex exhibits a slightly distorted trigonal bipyramidal geometry (τ = 0.89). The UV-vis spectrum of [Cu^II(TPMA^NMe2)Br]⁺ salts is similar to those of other pyridine-based ATRP catalysts. Electrochemical studies of [Cu(TPMA^NMe2)]²⁺ and [Cu(TPMA^NMe2)Br]⁺ showed highly negative redox potentials (E_1/2 = -302 and -554 mV vs SCE, respectively), suggesting unprecedented ATRP catalytic activity. Cyclic voltammetry (CV) in the presence of methyl 2-bromopropionate (MBrP; acrylate mimic) was used to determine activation rate constant k_a = 1.1 × 10⁶ M^-1 s^-1, confirming the extremely high catalyst reactivity. In the presence of the more active ethyl α-bromoisobutyrate (EBiB; methacrylate mimic), total catalysis was observed and an activation rate constant k_a = 7.2 × 10⁶ M^-1 s^-1 was calculated with values of K_ATRP ≈ 1. ATRP of methyl acrylate showed a well-controlled polymerization using as little as 10 ppm of catalyst relative to monomer, while side reactions such as Cu^I-catalyzed radical termination (CRT) could be suppressed due to the low concentration of L/Cu^I at a steady state.

6-Bromo-2-(1,4-dibromo-4-methylcyclohexyl)-6-methylheptan-4-one

The title compound, C15H25Br3O, was synthesized in one step from a mixture of α-atlantone [2-methyl-6-(4-methylcyclohex-3-en-1-yl)hepta-2,5-dien-4-one] and γ-atlantone [2-methyl-6-(4-methylcyclohex-3-en-1-ylidene)hept-2-en-4-one], which were isolated from an essential oil of the Atlas cedar (Cedrus Atlantica). The molecule is built up from the bromo ethyl cyclohexane ring, which has a substituent bromomethylhexanone group. The cyclohexane ring adopts a chair conformation. In the crystal, molecules are linked by C—H...O hydrogen bonds, forming zigzag chains parallel to [100].

(1R,2R,7S,8R,9R)-N-(2-Hydroxy-2,6,6,9-tetramethyl-12-oxatricyclo[7.2.1.01,7]dodecan-8-yl)acetamide

The title compound, C17H29NO3, was synthesized in two steps from β-himachalene (2,6,6,9-tetramethylbicyclo[5.4.01,7]undeca-1,8-diene), which was isolated from an oil of the Atlas cedar (Cedrus Atlantica). The asymmetric unit contains two independent molecules (A and B): B features an intramolecular O—H...O hydrogen bond whereas A forms an intermolecular O—H...O link to B. Each molecule is built up from a seven-membered ring to which a bridged six-membered ring is fused: the cycloheptane rings have twist-chair conformations, while the bridged cyclohexane rings display near-perfect boat conformations. In the crystal, the molecules are linked by N—H...O and O—H...O hydrogen bonds forming helical chains propagating along the b-axis direction. Some weak C—H...O interactions are also observed.

N-[1,4,4-Trimethyltricyclo[6.3.1.03,9]dodec-8(12)-en-2-yl]acetamide

The title compound, C17H27NO, crystallizes with three independent molecules in the asymmetric unit with almost identical conformations. Each molecule is built up from a seven-membered ring to which a bridged six-membered ring is fused. In each of the three molecules, the seven-membered rings have a twist-chair conformation, while the cyclohexenyl rings display perfect boat conformations. In the crystal, N—H...O hydrogen bonds link the molecules into zigzag chains running along theb-axis direction.

2-Isopropyl-4,7-dimethyl-1-nitronaphthalene

All the non-H atoms of the title compound, C15H17NO2, except the CH3groups of the isopropyl unit and the O atoms of the nitro group, lie on a crystallographic mirror plane. The dihedral angle between the naphthalene plane and the nitro group is constrained to be 90° by symmetry. In the crystal, molecules are linked by π–π interactions [centroid–centroid separation = 3.6591 (4) Å] and stacked along theb-axis direction.

Crystal and mol-ecular structure of (2Z,5Z)-3-(2-meth-oxy-phen-yl)-2-[(2-meth-oxy-phen-yl)imino]-5-(4-nitro-benzyl-idene)thia-zolidin-4-one

In the title compound, C24H19N3O5S, the thia-zole ring (r.m.s. deviation = 0.012 Å) displays a planar geometry and is surrounded by three fragments, two meth-oxy-phenyl and one nitro-phenyl. The thia-zole ring is almost in the same plane as the nitro-phenyl ring, making a dihedral angle of 20.92 (6)°. The two meth-oxy-phenyl groups are perpendicular to the thia-zole ring [dihedral angles of 79.29 (6) and 71.31 (7)° and make a dihedral angle of 68.59 (7)°. The mol-ecule exists in an Z,Z conformation with respect to the C=N imine bond. In the crystal, a series of C-H⋯N, C-H⋯O and C-H⋯S hydrogen bonds, augmented by several π-π(ring) inter-actions, produce a three-dimensional architecture of mol-ecules stacked along the b-axis direction. The experimentally derived structure is compered with that calculated theoretically using DFT(B3YLP) methods.

1-(7-Isopropyl-2,5-dimethyl-8-nitronaphthalen-1-yl)ethanone

The title compound, C17H19NO3, was synthesized in three steps from a mixture of α-, β- and γ-himachalene, which was isolated from an essential oil of the Atlas cedar (Cedrus atlantica). The dihedral angle between the two rings of the naphthalene moiety is 2.54 (5)°. The nitro group and the acetyl group lie almost normal to the mean plane of the naphthalene moiety, making dihedral angles of 80.29 (13) and 83.01 (15)°, respectively, and are inclined to one another by 13.23 (19)°. There is an intramolecular C—H...O hydrogen bond present involving a nitro O atom and the H atom of the methine C atom of the isopropyl group, forming an S(6) ring motif. In the crystal, molecules are linked by pairs of C—H...π interactions, forming inversion dimers. There are no other significant intermolecular interactions present.

Crystal structure of dimethyl 2-((2Z,5Z)-5-(2-meth-oxy-2-oxo-ethyl-idene)-2-{(E)-[2-methyl-5-(prop-1-en-2-yl)cyclo-hex-2-enyl-idene]hydrazinyl-idene}-4-oxo-thia-zolidin-3-yl)fumarate

The crystal structure and the conformation of the title compound, C22H27N3O7S, were determined from the synthetic pathway and by X-ray analysis. This compound is a new 4-thia-zolidinone derivative prepared and isolated as pure product from thio-semicarbazone carvone. The mol-ecule is built up from an oxo-thia-zolidine ring tetra-substituted by a meth-oxy-oxo-ethyl-idene, a maleate, an oxygen and a cyclo-hexyl-idene-hydrazone. The cyclo-hexyl-idene ring is statistically disordered over two positions, resulting in an inversion of configuration for the substituted carbon.

New Ferrocenyl Phenol Thiophosphines

Two new enantiomerically pure ferrocenyl phenol-thiophosphine compounds have been efficiently synthesized by a one pot procedure from enantiomerically pure alcohol (R)-(diphenylthiophosphinoferrocenyl)methanol 1 by a fully regioselective Friedel-Crafts reaction on phenols after strong acid activation. A mechanistic proposal through O-alkylation followed by rearrangement of the formed oxonium is proposed. All compounds have been and fully characterized by NMR(1H, 31P and 13C) and High Resolution Mass Spectroscopy. The molecular structure of one of these ferrocene derivatives have been determined by X ray diffraction analysis on monocrystal.

Platinum-catalysed intermolecular addition of carbonyl compounds to 1,6-enynes: investigation of a new reaction pathway

A novel intermolecular addition of aldehydes to 1,6-enynes via a Pt-carbene intermediate provides the diastereoselective formation of valuable tricyclic compounds.

Crystal structure of (1S,3R,8R,9R)-2,2-di-chloro-3,7,7-tri-methyl-10-methylenetri-cyclo-[6.4.0.0(1,3)]dodecan-9-ol

The title compound was synthesized by treating (1S,3R,8S,9R,10S)-2,2-di­chloro-3,7,7,10-tetra­methyl-9,10-ep­oxy­tri­cyclo­[6.4.0.0^1,3]dodecane with a concentrated solution of hydro­bromic acid. It is built up from three fused rings: a cyclo­heptane ring, a cyclo­hexyl ring bearing alkene and hy­droxy substituents, and a cyclo­propane ring bearing two chlorine atoms.

The title compound, C₁₆H₂₄Cl₂O, was synthesized by treating (1S,3R,8S,9R,10S)-2,2-di­chloro-3,7,7,10-tetra­methyl-9,10-ep­oxy­tri­cyclo­[6.4.0.0^1,3]dodecane with a concentrated solution of hydro­bromic acid. It is built up from three fused rings: a cyclo­heptane ring, a cyclo­hexyl ring bearing alkene and hy­droxy substituents, and a cyclo­propane ring bearing two chlorine atoms. The asymmetric unit contains two mol­ecules linked by an O—H⋯O hydrogen bond. In the crystal, further O—H⋯O hydrogen bonds build up an R₄⁴(8) cyclic tetra­mer. One of the mol­ecules presents disorder that affects the seven-membered ring. In both mol­ecules, the six-membered rings display a chair conformation, whereas the seven-membered rings display conformations inter­mediate between boat and twist-boat for the non-disordered mol­ecule and either a chair or boat and twist-boat for the disordered mol­ecule owing to the disorder. The absolute configuration for both mol­ecules is 1S,3R,8R,9R and was deduced from the chemical pathway and further confirmed by the X-ray structural analysis.

(1S,3R,8R,11S)-2,2,11-Tribromo-10-bromomethyl-3,7,7-trimethyltricyclo[6.4.0.01,3]dodec-9-ene

The title compound, C16H22Br4, was synthesized in two steps from β-himachalene, which was isolated from essential oil of the Atlas cedar (cedrus atlantica). It is built up from three fused rings, a seven-membered heptane ring, a six-membered cyclohexyl ring bearing both a bromine and a bromomethyl substituent, and a three-membered propane ring bearing two Br atoms. In the crystal, molecules are linked by C—H...Br hydrogen bonds, forming chains propagating along [001]. The absolute configuration was deduced from the chemical pathway and confirmed by resonant scattering [Flack parameter = 0.012 (10)].

Crystal structure of (1S,3R,8R,10S)-2,2-di-chloro-10-hy-droxy-3,7,7,10-tetra-methyl-tri-cyclo-[6.4.0.0(1,3)]dodecan-9-one

The asymmetric unit of the title compound, C16H24Cl2O2, contains two independent mol-ecules (A and B) which are built from three fused rings, viz. a seven-membered heptane ring, a six-membered cyclo-hexyl ring bearing a ketone and an alcohol group, and a cyclo-propane ring bearing two Cl atoms. In the crystal, the two mol-ecules are linked via two O-H⋯O hydrogen bonds, forming an A-B dimer with an R 2 (2)(10) ring motif. The A mol-ecules of these dimers are linked via a C-H⋯O hydrogen bond, forming chains propagating along the a-axis direction. Both mol-ecules have the same absolute configuration, i.e. 1S,3R,8R,10S, which is based on the synthetic pathway and further confirmed by resonant scattering [Flack parameter = 0.03 (5)].

N′-[(1S,3R,8R)-2,2-Dichloro-3,7,7,10-tetramethyltricyclo[6.4.0.01,3]dodecan-11-yl]acetohydrazide

The title compound, C18H26Cl2N2O, was synthesized in four steps from β-himachalene (3,5,5,9-tetramethyl-2,4a,5,6,7,8-hexahydro-1H-benzocycloheptene), which was isolated from an essential oil of the Atlas cedar (Cedrus atlantica). It crystallizes with two independent molecules in the asymmetric unit. Each molecule is built up from fused six- and seven-membered rings and an appended three-membered ring. An acetylhydrazone substituent is attached to the six-membered ring. In both molecules the six-membered rings display half-chair conformations, whereas the seven-membered rings have boat conformations. In the two molecules, the mean planes of the two rings are inclined to one another by 59.9 (3) and 59.1 (3)°. In the crystal, the two molecules are linkedviaN—H...O hydrogen bonds, forming dimers with anR22(8) loop. Within the dimer there are also C—H...O hydrogen bonds present. The dimers are linkedviaC—H...Cl hydrogen bonds, forming slabs parallel to theabplane.

Crystal structure of 2-[(3aS,6R)-3,3,6-trimethyl-3,3a,4,5,6,7-hexa-hydro-2H-indazol-2-yl]thia-zol-4(5H)-one

The title compound, C13H19N3OS, is a new thia-zolidin-4-one derivative prepared and isolated as the pure (3aS,6R)-diastereisomer from (R)-thio-semicarbazone pulegone. It crystallized with two independent mol-ecules (A and B) in the asymmetric unit. The compound is composed of a hexhydro-indazole ring system (viz. a five-membered di-hydro-pyrazole ring fused to a cyclo-hexyl ring) with a thia-zole-4-one ring system attached to one of the pyrazole N atoms (at position 2). The overall geometry of the two mol-ecules differs slightly, with the mean planes of the pyrazole and thia-zole rings being inclined to one another by 10.4 (1)° in mol-ecule A and 0.9 (1)° in mol-ecule B. In the crystal, the A and B mol-ecules are linked via C-H⋯O hydrogen bonds, forming slabs parallel to the ab plane. There are C-H⋯π inter-actions present within the layers, and between the layers, so forming a three-dimensional structure.