Borate Ruthenium Research Articles

Divergent Synthesis of Molecular Winch Prototypes.

We report the synthesis of conceptually new prototypes of molecular winches with the ultimate aim to investigate the work performed by a single ruthenium-based molecular motor anchored on a surface by probing its ability to pull a load upon electrically-driven directional rotation. According to a technomimetic design, the motor was embedded in a winch structure, with a long flexible polyethylene glycol chain terminated by an azide hook to connect a variety of molecular loads. The structure of the motor was first derivatized by means of two sequential cross-coupling reactions involving a penta(4-halogenophenyl)cyclopentadienyl hydrotris(indazolyl)borate ruthenium(II) precursor and the resulting benzylamine derivative was next exploited as key intermediate in the divergent synthesis of a family of nanowinch prototypes. A one-pot method involving sequential peptide coupling and Cu-catalyzed azide-alkyne cycloaddition was developed to yield four loaded nanowinches, with load fragments encompassing triptycene, fullerene and porphyrin moieties.

ChemInform Abstract: Desymmetrization on Both Ligands of Pentaphenylcyclopentadienylhydrotris(indazolyl) Borate Ruthenium(II) Complexes: Prototypes of Organometallic Molecular Gears and Motors

AbstractReview: 73 refs.

Picolyl–NHC Hydrotris(pyrazolyl)borate Ruthenium(II) Complexes: Synthesis, Characterization, and Reactivity with Small Molecules

Ruthenium(II) hydrotris(pyrazolyl)borate chloro complexes bearing picolyl-functionalized N-heterocyclic carbenes [TpRu(κ(2)-C,N-picolyl-(R)I)Cl] (picolyl-(Me)I = 3-methyl-1-(2-picolyl)imidazol-2-ylidene) (1a), picolyl-(iPr)I = 3-isopropyl-1-(2-picolyl)imidazol-2-ylidene (1b), picolyl-(Me)45DClI = 3-methyl-1-(2-picolyl)-4,5-dichloroimidazol-2-ylidene (1c), picolyl-(Ph)I = 3-phenyl-1-(2-picolyl)imidazol-2-ylidene (1d), picolyl-(Me)BI = 3-methyl-1-(2-picolyl)benzoimidazol-2-ylidene (1e)) have been synthesized and characterized. Furthermore, cationic carbonyl derivatives 2a-e have been prepared, characterized, and used to study the donor properties of the picolylcarbene ligands (picolyl-(R)I) via infrared spectroscopy. Also, the reactivity of the 16-electron species [TpRu(κ(2)-C,N-picolyl-(R)I)](+), in situ generated using NaBAr(F)4 (Ar(F) = 3,5-bis(trifluoromethyl)phenyl) as a halide scavenger, toward N2, CH3CN, H2, CH2CH2, S8, and O2 was studied indicating a strong influence of the NHC wingtip and backbone substituents in the product distribution. The crystal structures of [TpRu(κ(2)-C,N-picolyl-(iPr)I)Cl] (1b), [TpRu(κ(2)-C,N-picolyl-(Me)I)CO][BAr(F)4] (2a), [TpRu(κ(2)-C,N-picolyl-(Ph)I)CO][BAr(F)4] (2d), [{TpRu(κ(2)-C,N-picolyl-(Me)I}2(μ-N2)][BAr(F)4]2 (3'a), [{TpRu(κ(2)-C,N-picolyl-(Ph)I)}2(μ-N2)][BAr(F)4]2 (3'd), [TpRu(κ(2)-C,N-picolyl-(iPr)I)(η(2)-CH2CH2)][BAr(F)4] (5b), and [{TpRu(κ(2)-C,N-picolyl-(Me)I)}2(μ-S2)][BAr(F)4]2 (6) are reported.

Isomerization of Internal Alkynones to Vinylidenes in Tris(pyrazolyl)borate Ruthenium Complexes. Solution and Solid-State Kinetics

Internal alkynones of the type PhC≡CCOR (R = Ph, Me) undergo thermal isomerization to disubstituted vinylidenes, Ru═C═C(COR)Ph in the coordination sphere of tris(pyrazolyl)borate ruthenium complexes. The treatment of [TpRuCl(PiPr2Me)(MeCN)] and [TpRuCl(iPr2PNHPy)] with NaBArF4 (ArF = 3,5-bis(trifluoromethyl)phenyl) and the corresponding alkynone yields η1-O-ketone complexes as kinetic products. These species are metastable and spontaneously isomerize to disubstituted vinylidenes both in solution and in the solid state. Kinetic studies in solution show that the isomerization rate is first-order in the concentration of the ketone complex, and thus the activation parameters have been obtained from Eyring plots. A concerted sigmatropic 1,2-acyl shift is proposed as the key step. The isomerization in the solid-state has been studied by IR spectroscopy and the results interpreted with the Avrami−Erofeev model. The X-ray structure of a disubstituted vinylidene complex has been determined for the complex [TpRu{═C...

Antitumor activity of new hydridotris(pyrazolyl)borate ruthenium(ii) complexes containing the phosphanes PTA and 1-CH3–PTA

The synthesis and full characterization of new half-sandwich ruthenium(II) complexes containing κ(3)(N,N,N)-hydridotris(pyrazolyl)borate (κ(3)(N,N,N)-Tp) and the water-soluble phosphanes 1,3,5-triaza-7-phosphatricyclo[3.3.1.1(3,7)]decane (PTA) and 1-methyl-3,5-diaza-1-azonia-7-phosphatricyclo[3.3.1.1(3,7)]decane (1-CH(3)-PTA) has been explored. Single crystal X-ray diffraction analysis for complex [RuCl{κ(3)(N,N,N)-Tp}(PMe(2)Ph)(1-CH(3)-PTA)][CF(3)SO(3)]·2NCMe is also reported. DNA binding properties of the ruthenium complexes have been evaluated by mobility shift assay and MALDI-TOF mass spectrometry. The in vitro antitumor activity of these compounds was assessed by examining their ability to inhibit cell proliferation in a number of human cancer cell lines (NCI-H460, SF-268, MCF-7) and non-tumor human umbilical vein endothelial cells (HUVEC). Some of these new compounds show promising cytotoxic activity with IC(50) values in the low micromolar range, and display differential effects on cancer and normal cell growth.

Directed synthesis of symmetric and dissymmetric molecular motors built around a ruthenium cyclopentadienyl tris(indazolyl)borate complex

This article focuses on the synthesis of a family of rotary molecular motors based on a penta-substituted cyclopentadienyl tris(indazolyl)borate ruthenium(II) complex. In order to demonstrate a movement of rotation in this family of molecular motors, dissymmetric derivatives with one ferrocene missing have also been synthesized. The molecules have been prepared with ester and thioether-functionalized tris(indazolyl)borate ligands in view of studying them as single molecules on various surfaces by STM or AFM techniques.

ChemInform Abstract: Catalytic Transformations of Terminal Alkynes by Cationic Tris(1‐pyrazolyl)borate Ruthenium Catalysts: Versatile Chemistry via Catalytic Allenylidene, Vinylidene, and π‐Alkyne Intermediates

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Catalytic Transformations of Terminal Alkynes by Cationic Tris(1-pyrazolyl)borate Ruthenium Catalysts: Versatile Chemistry via Catalytic Allenylidene, Vinylidene, and π-Alkyne Intermediates

In this report, we describe the catalytic activation of terminal alkynes using TpRuPPh 3 (MeCN) 2 X (X = PF 6 and SbF 6 ) complexes. These ruthenium species enable transformation of terminal alkynes into π-alkyne, vinylidene, and allenylidene intermediates, and provide new catalytic reactions via three different pathways. Due to the cationic nature and the coordinative unsaturation around the ruthenium center, we observed the formation and scission of new types of C-X (X = O, N, C) bonds occurring in the catalytic transformations of terminal alkynes, as well as structurally reorganized products. This review summarizes some important examples. 1 Introduction 2 Allenylidene Intermediate 2.1 Internal Redox Reaction 2.2 Cleavage of Carbon-Carbon Triple Bond 3 Vinylidene Intermediate 3.1 Cyclization of CIS-3-En-1-ynes 3.2 Cyclization of CIS-3-Eny-1-nyl Epoxides 3.3 Cyclization of 3,5-Dien-1-ynes 3.4 Cyclization of 3,5-Dien-1-ynes with Skeletal Rearrangement 3.5 Cyclization of 2′,2′-Disubstituted (o-ethynyl)styrenes 4 π-Alkyne Intermediates 4.1 Cyclization of Acyclic 6,6-Disubstituted 3,5-Dien-1-ynes 4.2 Aromatization of Enediynes with Catalytic Nucleophilic Additions 4.3 Aromatization of Endiynes with Catalytic C-H Bond Insertion 5 Concluding Remarks

Novel hydridotris(pyrazolyl)borate ruthenium(II) complexes containing the water-soluble phosphane 1,3,5-triaza-7-phosphaadamantane: Synthesis and evaluation of DNA binding properties

A series of half-sandwich ruthenium(II) complexes containing κ 3( N, N, N)-hydridotris(pyrazolyl)borate (κ 3( N, N, N)-Tp) and the water-soluble phosphane 1,3,5-triaza-7-phosphaadamantane (PTA) [RuX{κ 3( N, N, N)-Tp}(PPh 3) 2− n (PTA) n ] ( n = 2, X = Cl ( 1), n = 1, X = Cl ( 2), I ( 3), NCS ( 4), H ( 5)) and [Ru{κ 3( N, N, N)-Tp}(PPh 3)(PTA)L][PF 6] (L = NCMe ( 6), PTA ( 7)) have been synthesized. Complexes containing 1-methyl-3,5-diaza-1-azonia-7-phosphaadamantane(m-PTA) triflate [RuCl{κ 3( N, N, N)-Tp}(m-PTA) 2][CF 3SO 3] 2 ( 8) and [RuX{κ 3( N, N, N)-Tp}(PPh 3)(m-PTA)][CF 3SO 3] (X = Cl ( 9), H ( 10)) have been obtained by treatment, respectively, of complexes 1, 2 and 5 with methyl triflate. Single crystal X-ray diffraction analysis for complexes 1, 2 and 4 have been carried out. DNA binding properties by using a mobility shift assay and antimicrobial activity of selected complexes have been evaluated.

Facileγ-C−H Bond Activation in Phosphinoamine Ligands Resulting in Regio- and Stereoselective C−C Coupling with Terminal Acetylenes

Novel C−C coupling products are afforded from the reaction of tris(pyrazolyl)borate ruthenium complexes, containing the phosphinoamine ligands Ph2PCH2CH2NMe2, Ph2PCH2CH2NEt2, and Ph2PCH2CH2NiPr2, with terminal acetylenes (see scheme). The coupling takes place regioselectively at the γ-carbon atom of the phosphinoamine ligand and, depending on the steric requirments of R, either at the internal or terminal carbon atom of the acetylene molecule. All these reactions proceed in a highly diastereoselective fashion.

Facile -C−H Bond Activation in Phosphinoamine Ligands Resulting in Regio- and Stereoselective C−C Coupling with Terminal Acetylenes

Novel C−C coupling products are afforded from the reaction of tris(pyrazolyl)borate ruthenium complexes, containing the phosphinoamine ligands Ph2PCH2CH2NMe2, Ph2PCH2CH2NEt2, and Ph2PCH2CH2NiPr2, with terminal acetylenes (see scheme). The coupling takes place regioselectively at the γ-carbon atom of the phosphinoamine ligand and, depending on the steric requirments of R, either at the internal or terminal carbon atom of the acetylene molecule. All these reactions proceed in a highly diastereoselective fashion.