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7,8-Dihydro-1,4-diphosphabarrelene diselones and bis(NHCs) were synthesised and employed as multitopic P,Se and P,C ligands in coordination chemistry, benefitting from a unique bent, P-bridged topology, thus being promising new building blocks. [ABSTRACT FROM AUTHOR]

The synthesis of five-membered P-heterocyclic iron(0) complexes possessing a P–H unit and two heteroatoms (E = O, N), directly bound to phosphorus, is described. Initial problems to achieve access via "classical" reduction of P–Cl bonds of P-heterocycle complexes, e.g., leading to P–P coupling, could be solved by a "combined two-step" reduction/complexation. The use of K[Fe(CO)4H] not only opened access to such heterocyclic phosphane Fe(CO)4 complexes but also allowed the synthesis of sterically non-shielded 'secondary' heterocyclic phosphane complexes. Spectroscopic and structural parameters are discussed. [ABSTRACT FROM AUTHOR]

The current study was performed to synthesize novel arylated pyridine derivatives viz; 2,6-bis(benzothiophen-2-yl)pyridine (PB1), 2-bromo-6-(2-bromophenyl)pyridine (PB2), 2,6-bis(2-bromophenyl)pyridine (PB3) and 2-(benzo[b]thiophen-2-yl)-6-bromopyridine (PB4), through well-known Suzuki-Miyaura Pd0-catalyzed protocol. Different characterization techniques such as UV-Visible, FT-IR, 13C-NMR, 1H-NMR, and single-crystal X-ray diffraction (SC-XRD) analysis were used for the structure elucidation of synthesized compounds. The SC-XRD results demonstrated that the crystal system of the novel compounds PB1 and PB2 was orthorhombic and monoclinic, and their space group was found to be P212121 and P21/n, respectively. The computational quantum analysis of the investigated entities was conducted using density functional theory (DFT). The geometry was optimized using the M06-2X and 6-311++G(d,p) functional. The same functional was also utilized to investigate natural bond orbitals (NBOs). At the same time, the time-dependent density functional theory (TD-DFT) was applied to examine the frontier molecular orbitals (FMOs) and the UV-Visible spectrum, which also gave Global reactivity parameters (GRPs) values. The NBO investigation proved that the stability was caused by hyper-conjugative interactions. Data from FMO and NBO were used to validate the intramolecular charge transfer (ICT) mechanisms in the compounds under study. The non-linear optical (NLO) characteristics were assessed by means of the LC-BLYP, HF, and M06-2X techniques with the 6-311++G(d,p) basis set. The analysis of NLO indicated encouraging NLO response for all the compounds that were examined. [ABSTRACT FROM AUTHOR]

Dinuclear phosphinidene complexes bridging two transition metal centres are now well established. However, a phosphinidene bridging a metal centre and a main group Lewis acid has not yet been reported. Herein, we describe the generation of a highly reactive phosphinidene complex bridging a tungsten and a boron centre. Furthermore, the synthesis and dyotropic rearrangement of a P-borane adduct of an N-methylimidazole-stabilized neutral, electrophilic terminal phosphinidene complex is reported. [ABSTRACT FROM AUTHOR]

Novel tricyclic 1,4-dihydro-1,4-phosphagermines (3a and 4a) were synthesised from Ge(NR2)2-bridged 1,3-imidazole-2-thione derivative 2a; all structures were crystallographically confirmed. In going from rather small alkyl substituents (Me, nBu) at the nitrogen centers of the 1,3-imidazole-2-thione units to sterically more demanding R = Mes and changing the employed Ge reagent from (R2N)2GeCl2 to R2NGeCl3 we achieved access to mixed functional bis(1,3-imidazole-2-thione)-substituted germanium derivative 2c. The latter was treated with MeLi and, subsequently, with PCl3 to yield a pentacyclic P,Ge-heterocycle (5); its formation was rationalized using DFT theoretical calculations. [ABSTRACT FROM AUTHOR]

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Phospha-Wittig reagents such as phosphanylidene-phosphoranes and their transition metal complexes are of great interest as sources of P1 building blocks but the access is still limited. Herein, we describe a new access to phosphanylidene-phosphorane complexes starting from the N-methylimidazole-to-phosphinidene complex adduct. The complexes were studied electrochemically and theoretically, also with respect to their 31P NMR data, and the P-P bonds were evaluated by various DFT-derived descriptors. [ABSTRACT FROM AUTHOR]

A gene coding for a terpene synthase homolog from Kitasatospora viridis was cloned and expressed in Escherichia coli. The purified recombinant protein possessed sesterterpene synthase activity and efficiently converted geranylfarnesyl diphosphate (GFPP) with 19 % yield into the sesterterpene hydrocarbon sesterviridene A. Large scale enzymatic conversions also allowed for the isolation of two side products that are generated with very low yields of ca. 0.1 %. Several derivatives of sesterviridene A were obtained by chemical transformations, securing the NMR‐based structural assignments. The absolute configuration of sesterviridene A was determined by chemical correlation using stereoselectively deuterated precursors and by anomalous dispersion X‐ray crystallography. The cyclisation mechanism from GFPP to sesterviridene A was extensively studied through isotopic labelling experiments and DFT calculations. [ABSTRACT FROM AUTHOR]

Metal complexes displaying antiplatelet properties is a promising research area. In our methodology, Platelet-Activating Factor (PAF), the most potent lipid pro-inflammatory mediator, serves as a biological probe. The antiplatelet activity is exerted by the inhibition of the PAF-induced aggregation in washed rabbit platelets (WRPs) and in rabbit plasma rich in platelets (rPRPs). Herein, the synthesis and biological investigation of a series of organometallic tin(II) and tin(IV) complexes, featuring the oxygen tripodal Kläui ligands [(η5-C5R5)Co{P(OEt)2O}3]−, {R = H, (LOEt−); Me (L*OEt−)}, are reported. Reaction of NaLOEt (1a) and NaL*OEt (1b) with SnCl2, yielded the rare four-coordinate LOEtSnCl (2a) and L*OEtSnCl (2b) complexes. Accordingly, LOEtSnPh3 (3a) and L*OEtSnPh3 (3b) were prepared, starting from Ph3SnCl. Characterization includes spectroscopy and X-ray diffraction studies for 2a, 2b and 3b. The antiplatelet activity of the lead complexes 2b and 3a (IC50 = 0.5 μΜ) is superior compared to that of 1a and 1b, while both complexes display a pronounced inhibitory activity against thrombin (IC50 = 1.8 μM and 0.6 μM). The in vitro cytotoxic activities of 3a and 2b on human Jurkat T lymphoblastic tumor cell line is higher than that of cisplatin. [ABSTRACT FROM AUTHOR]