16373-02-7

The improved synthesis of Jacobsen catalyst 1 was developed. For both enantiomers the obtained overall yield starting from commercially available 4 was 80-85%.

Herein, we present a fundamental study of isostructural 2-methoxyethylamino-bis(phenolate)-lanthanide complexes [(ONOO)RM(X)(THF)] (M = Lu, Y; R = tBu, CMe2Ph, X = CH2TMS, collidine; THF = tetrahydrofuran; TMS =

A new, considerably improved cycloSal masking group has been developed. This new group combines four desirable properties and has been attached to the anti-HIV drug 2′,3′-dideoxy-2′,3′-didehydrothymidine (d4T, 1) to give 3,5-(di-tert-butyl)-6-fluoro-cycloSal-d4TMP (2i). This phosphate triester has a reasonable chemical half-life, highly selectively released d4TMP, has poor - if any - inhibitory effect on butyrylcholinesterase (BChE), and achieved the TK-bypass. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003).

Herein, we report two newly synthesized salen-type ligands, 2,3-bis((3,5-di-tert-butyl-2-hydroxybenzyl)thio)maleonitrile (H2L1) and 2,3-bis((3,5-di-tert-butyl-2-hydroxybenzyl)amino)malenonitrile (H4L2), bearing different coordination sites (sulfur vs amine) at maleonitrile tethered moiety to investigate metal mediated non-innocence chemistry of these ligands. Upon metallation, ligand H2L1 did not yield simple metal-ligand complex, rather ligand was split into two organic fragments, dithiolene moiety (mnt)2? and phenol moiety via C?S bond cleavage wherein (mnt)2? formed a stable metal complex [M(mnt)2]2?. The C?S bond cleavage was interpreted in terms of strong p(π) … d(π) interaction between metal and dithiolene moiety in H2L1 ligand that invoked the intramolecular rearrangement facilitating C?S bond cleavage. Interestingly, the phenol moiety further transformed to either unprecedented 2,4-di-tert-butyl-6-methylenecyclohexa-2,4-dienone (i. e. spiro compound; 5) or 2,4-di-tert-butyl-6-(hydroxymethyl)phenol (6) depending on the temperature of reaction and type of metal ion used which was further predicted using DFT calculation. On the other hand, combined experimental and DFT studies explained that upon metallation, ligand H4L2 yielded non-cleavage [M(H2L2)] (3 for M=Cu(II) and 4 for M=Ni(II)) complex, which slowly oxidized at ?NH?CH2-(amine) region to ?N=CH? (imine) in H2L2 ligand under aerobic environment via C?H bond activation, yielding [CuII(L3)] (1) (or [NiII(L3)] (2) complex (H2L3=oxidatively dehydrogenated product of H4L2 ligand.

The invention discloses a PNO ligand containing planar chiral ferrocene and application thereof. The PNO ligand containing planar chiral ferrocene is a planar chiral ferrocene-containing and phenol-containing PNO ligand as shown in a general formula (I) or (II) which is described in the specification, or a planar chiral ferrocene-containing and aryl-phosphoric-acid-containingPNO ligand containing as shown in a general formula (III) or (IV) which is described in the specification, or a planar chiral ferrocene-containing and carbon-chiral-phenol-containingPNO ligand as shown in a general formula (V) or (VI) which is described in the specification. The invention provides tridentate PNO ligands and processes for their complexation with transition metal salts or transition metal complexes; the introduction of salicylaldehyde and derivatives thereof, which are simple and easy to obtain, enables the ligands to have a bifunctionalization effect, and -OH in a formed catalyst has stronger acidity and is beneficial to combination with N/O in polar double bonds. Therefore, due to the bifunctionalization effect of the catalyst, the interaction between the catalyst and a substrate can be greatly improved, so a reaction can obtain higher catalytic activity and stereoselectivity.

PROBLEM TO BE SOLVED: To provide a novel cerium carbene complex suitable for LED phosphors, organic EL emission layer materials, wavelength conversion materials for solar cells, and wavelength conversion materials for agriculture facility, and a method of producing the same. SOLUTION: The present invention provides a cerium complex with trivalent cerium coordinated with a carbene compound; particularly, a cerium complex in which the carbene compound coordinated to trivalent cerium being represented by formula (1). (R1, R2, R3, R4, R5, R6, R7, R8, R9, R10 each represent a hydrogen atom, or a C1-20 hydrocarbon group, or a hydrocarbon group containing an oxygen atom or a phosphorus atom, where they may be bound to each other, to form a ring. R11, R12 each represent a hydrogen atom or a C1-20 hydrocarbon group, where they may be bound to each other, to form a ring. x is an integer of 0 to 10). SELECTED DRAWING: None COPYRIGHT: (C)2019,JPOandINPIT

The invention relates to a Salen-Fe-like complex, and a preparation method and application thereof. The structure of the complex is disclosed in the specification. The preparation method comprises the following steps: carrying out a two-step process on cy

Phenolato moieties impart redox flexibility to metal complexes due their accessible (oxidative) redox chemistry and have been proposed as functional ligand moieties in redox non-innocent ligand based transition metal catalysis. Here, the electro- and spectroelectrochemistry of phenolato based μ-oxodiiron(III) complexes [(L1)Fe(μ-O)Fe(L1)]2+ (1) and [(L2)Fe-(μ-O)Fe(L2)]2+ (2), where L1 = 2-(((di(pyridin-2-yl)methyl)-(pyridin-2-ylmethyl)amino)methyl)phenol and L2 = 3, 5-di-tert-butyl-2-(((di(pyridin-2-yl)methyl)(pyridin-2-ylmethyl)amino)-methyl)phenol, is described. The electrochemical oxidation of 1 in dichloromethane results in aryl C-C coupling of phenoxyl radical ligand moieties to form tetra nuclear complexes, which undergo subsequent oxidation to form iron(III) phenolato based polymers (poly-1). The coupling is blocked by placing tert-butyl groups at para and ortho positions of phenol units (i.e., 2). Poly-1 shows two fully reversible redox processes in monomer free solution. Assignment of species observed during the electrochemical and chemical {(NH4)2[CeIV(NO3)6]} oxidation of 1 in acetonitrile is made by comparison with the UV-vis-NIR absorption and resonance micro-Raman spectroelectrochemistry of poly-1, and by DFT calculations, which confirms that oxidative coupling occurs in acetonitrile also. However, in contrast to that observed in dichloromethane, in acetonitrile, the oligomers formed are degraded in terms of a loss of the Fe(III)-O-Fe(III) bridge by protonation. The oxidative redox behavior of 1 and 2 is, therefore, dominated by the formation and reactivity of Fe(III) bound phenoxyl radicals, which considerably holds implications in regard to the design of phenolato based complexes for oxidation catalysis.

The invention discloses a salen-like compound which has a structural formula shown in the specification. The compound has high selectivity and high sensitivity against Zn; and after the compound is added into an acetonitrile solution of a sample to be

Congeneric complexes (S)-{?O}MCH2SiMe3 (M=Al, 3; Ga, 5; In, 6) of the triel metals supported by an enantiomerically pure phenolato-alkoxo {?O}2- dianionic tridentate ligand derived from prolinol, along with their chloro derivatives, have been prepared and characterised. The aluminium-alkyl species (S)-{?O}AlMe and 3 form four-coordinate complexes with slightly distorted tetrahedral geometries, whereas the geometry in the Lewis acidic five-coordinate (S)-{?O}GaCl·THF is a distorted trigonal bipyramid. These alkyl complexes do not react cleanly, if at all, with protic sources. The indium(III) compound 6, which is for instance inert towards iPrOH or BnOH even after hours at 70°C, catalyses at 95°C the controlled, immortal ring-opening polymerisation of racemic lactide (up to 1000 equivalents) in the presence of excess BnOH as a chain transfer agent. It affords atactic, monodisperse polylactides with predictable molecular weights.

A cyclic diamine ligand whose core structure was derived from Tr?ger's base, and included additional pendant arms containing ancillary donor coordination sites was prepared and coordination with transition metals attempted.

A series of dinuclear aluminum complexes 1-4 stabilized by amine-bridged poly(phenolato) ligands have been synthesized, which are highly active in catalyzing the cycloaddition of epoxides and CO2. In the presence of 0.3 mol % complex 3 and 0.9 mol % NBu4Br at 1 bar CO2 pressure, terminal epoxides bearing different functional groups were converted to cyclic carbonates in 60-97% yields. Complex 3 is one of the rare examples of Al-based catalysts capable of promoting the cycloaddition at 1 bar pressure of CO2. Moreover, reactions of more challenging disubstituted epoxides also proceeded at an elevated pressure of 10 bar and afforded cyclic carbonates in 52-90% yields.

A series of tridentate aryloxy-based ligands were synthesized and characterized for their coordination behaviour towards TiIV. Coordination studies revealed that the nature of the central atom (amine vs. ether) and the type of bridging spacer (aromatic vs. aliphatic) are important aryloxy ligand parameters and influence the ligand coordination mode and the formation of stable titanium complexes. This series of titanium complexes were evaluated in ethylene oligomerization and polymerization after activation with methylaluminoxane (MAO) and showed the preferential formation of polyethylene. In some cases, the formation of a small amount of 1-hexene suggests the existence of several catalytic centres in the reaction mixture.

We report herein the use of the (dihydrido)iron catalyst, Fe(H)2(dmpe)2, for the selective reduction of CO2 into either bis(boryl)acetal or methoxyborane depending on the hydroborane used as a reductant. In a one-pot two-step procedure, the in situ generated bis(boryl)acetal was shown to be a reactive and versatile source of methylene to create new C-N but also C-O and C-C bonds.

Chiral iron(iii)-salan complexes catalysed highly enantioselective α-fluorination and α-hydroxylation of β-keto esters and N-Boc oxindoles to give the corresponding products in high yields and good-to-excellent ee values under mild reaction conditions. This journal is the Partner Organisations 2014.

The activity of several group 4 metal alkoxide complexes supported by ferrocene-based ligands was controlled using redox reagents during the ring-opening polymerization of l-lactide and ε-caprolactone. Switching in situ between the oxidized and reduced fo

Multigram amounts of halogen-free aluminate salts were prepared from cost-efficient ethylene-bridged bisphenols and alkali aluminium hydrides. The lipophilic, weakly-coordinating "aletbate" anion with eight tert-butyl substituents, the "aletpate" anion wi

The dinuclear magnesium complexes generated in situ from the reaction of chiral multidentate semi-azacrown ether ligands with n-Bu2Mg were found to be efficient catalysts for enantioselective ring-opening of meso-epoxides with aniline derivativ

Metal phosphonates [Zn2(dtbhp)2(TMEDA) 2(H2O)2]·0.5CH3CN (1), Cd2(dtbhp)2(TMEDA)2(H2O) 2]·0.5CH3CN (2), [Cd2(mdtbhp)2(1,10-

A series of N2O2 tripodal tetradentate ligands derived from di-/tetra-tert-butyl substituted 2-[bis(2-hydroxybenzyl) aminomethyl]X (X = pyridine and benzimidazole) (H2Ln (n = 1-4)) and 8-[bis(3,5-di-tert-butyl-2-hydroxybenzyl)]aminoquinoline (H 2L5) were synthesised through a 4-step reaction scheme involving sequential formylation, reduction, bromination and alkylation. Treatment of H2Ln (n = 1-5) with [WO2Cl 2(dme)] (dme = 1,2-dimethoxyethane) in the presence of triethylamine gave the corresponding cis-dioxotungsten(vi) complexes [WO2(L n)] (n = 1-5). The corresponding molybdenum analogues [MoO 2(Ln)] (n = 1-5) were also prepared from the reaction of [MoO2(acac)2] (acac = acetylacetonate) with H 2Ln (n = 1-3) or [MoO2Cl2(dme)] (dme = 1,2-dimethoxyethane) with H2Ln (n = 4 and 5). All these compounds were fully characterised by a wide range of spectroscopic methods. The molecular structures of [MoO2(Ln)] (n = 2, 4) and [WO2(L2)] were also confirmed by single-crystal X-ray diffraction analysis. The catalytic activities of [MO2(L n)] (M = Mo, W; n = 1-4) towards epoxidation of styrene were also examined.

A new synthetic route to the known tripodal tetradentate N3O ligand L1 (HL1 = [N-(3,5-di-tert-butyl-2-hydroxybenzyl)-N,N-di-(2-pyridylmethyl)]amine) is reported. The related compounds HLn (n = 2, 3) were prepared by a similar procedure. Treatment of HLn (n = 1-3) with FeCl3·6H2O in hot methanol led to the mononuclear iron(III) complexes [Fe(Ln)Cl2] (1: n = 1, 2: n = 2, 3: n = 3). The solid-state structures of complexes 1 and 2 were determined by X-ray crystallography. [Fe(L1)Cl2] (1) showed effective nuclease activity in the presence of hydrogen peroxide, converting supercoiled plasmid DNA to its linear form.

The reduction of hydroxyl-substituted aromatic carboxylic acid with NaBH4/Me2SO4/B(OMe)3 is described. Borane is generated by the reaction of NaBH4 with Me2SO4 in THF, which is as efficient as the commercial one. B(OMe)3 has been successfully applied to increase the reactivity and selectivity of this reaction. The optimum ratio of borane/B(OMe)3/acid is studied, and a variety of hydroxyl-substituted aromatic acids are reduced in good yields.

(Chemical Equation Presented) Efficient benzylic radical formation from benzo[d]-1,2-oxaphospholes has demonstrated their suitability as precursors of stabilized C-centered radicals, a property associated with antioxidant potential. A remarkable stereodifferentiation is observed for alkyl- and aryl-substituted derivatives.

Reaction of 2,4-di-tert-butylphenol with urotropin in conditions of Duff reaction takes an abnormal route and instead of the expected di-tert-butylsalicylaldehyde provides a mixture of N-substituted 3,5-di-tert-butyl-2-hydroxybenzylamines and redox conjugate benzoxazines containing mostly 6,8-di-tert-butyl-3-(3,5-di-tert-butyl-2-hydroxybenzyl)-2H-3, 4-dihydrobenz[e][1,3]oxazine. A solvolysis of an individual benzoxazine in the system HO(CH2)2OH-H2O-HCl affords di(3,5-di-tert-butyl-2-hydroxybenzyl)amine, and in AcOH 3,5-di-tert- butylsalicilaldehyde. A mechanism of Duff reaction was suggested involving the formation of a benzoxazine intermediate. 2005 Pleiades Publishing, Inc.

Several ligands for a new type of Lewis acid, which incorporates two linked phenols, were synthesized and the reaction of these ligands with trimethylaluminum quantitatively gave Lewis acids. These Lewis acids were found to be an efficient promoter for the rearrangement of epoxides to carbonyl compounds as well as a useful protector of acetophenone against hydride-reduction. The VT-NMR spectrum and NOESY spectrum of a 1:1 complex of Lewis acid 2a (methyl[2,2′-(m-xylene-α,α′-diyl)bis(4,6-di-t- butylphenoxido)aluminum and acetophenone provided data on the structure of a complex of acetophenone and 2a.

A series of phenoxyl radical complexes of zinc(II) have been generated in solution and, in one instance, isolated as solid material (5) in order to study their spectroscopic features by EPR, resonance Raman, and UV-vis spectroscopy. They serve as model complexes for the active form of the copper containing fungal enzyme galactose oxidase. The complexes [Zn(L1H2)]BF4·H2O (1), [Zn(L2H2)]BF4·H2O (2), [Zn(L2H)] (2a), [Zn(L3)(Ph2acac)] (3), [Zn(L4)(Ph2acac)] (4), and [Zn(L4)(Me-acac)] (6) were synthesized from solutions of Zn(BF4)2·4H2O and the corresponding ligand (L1H3 = 1,4,7-tris(3,5-tert-butyl-2-hydroxybenzyl)-1,4,7-triazacyclononane; L2H3 = 1,4,7-tris-(3-tert-butyl-5-methoxy-2-hydroxybenzyl)- 1,4,7-triazacyclononane; L3H = 1,4-dimethyl-7-(3,5-di-tert-butyl-2-hydroxybenzyl)-1, 4,7-triazacyclononane; L4H 1,4-dimethyl-7-(3-tert-butyl-5-methoxy-2-hydroxybenzyl)-1,4,7 -triazacyclononane, Ph2acac- = 1,3-diphenyl-1,3-propanedionate, and Me-acac- = 3-methyl-2,4-pentanedionate). Complexes 2, 3·0.5 toluene·1n-hexane, and 4 were structurally characterized by single-crystal X-ray crystallography. An electrochemical investigation of these complexes in CH3CN and/or CH2Cl2 solution revealed that the coordinated phenolate ligands undergo reversible one-electron oxidations with formation of coordinated phenoxyl radicals. Synthetically, the microcrystalline, paramagnetic (μ(eff) = 1.7 μ(B)), solid material of [Zn(L4)(Ph2acac)]PF6 (5) was produced by one electron oxidation of 4 by 1 equiv of ferrocenium hexafluorophosphate in dry CH2Cl2. Oxidation of coordinated phenol pendent arms in 1, 2, and 2a occurs at significantly higher potentials and is irreversible. Electronic (UV-vis), electron paramagnetic resonance (EPR), and resonance Raman (RR) spectra of the radicals have been studied in solution and allow the description of the electronic structure of these coordinated phenoxyl radical complexes.

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A study was carried out on the condensation of 2,4-di-tert-butylphenol with paraformaldehyde under alkaline conditions, which proceeds either with the formation of the corresponding benzyl alcohol or diarylmethane depending on the metal hydroxide, quantity of alkali, and ratio and order of addition of the reagents.

A class of zinc(II) chelates with chiral tertiary amino phenolic alcohols serve as effective catalysts for the enantioselective addition of diethylzinc to aromatic aldehydes with predictable absolute stereochemistry.

Substituted 2-(2,6-di-t-butyl-4-alkylphenoxy)-4H-1,3,2-benzodioxaphosphorins that are readily prepared, for example from hindered phenols and ortho-methylolphenols, are effective heat and anti-oxidant stabilizers for organic materials subject to degradation by heat and oxygen, and provide particularly efficient stabilizer systems when combined with hydroxyphenylalkyleneyl isocyanurates.

The 1-oxaspiroocta-5,7-dien-4-ones (6-spiroepoxy-2,4-cyclohexadienones) (7) on reaction with a number of carbon, nitrogen, oxygen and halogen nucleophiles produced a variety of interesting substitution and rearrangement products (8)-(19) in moderate yields.The products derived almost exclusively from initial attack of the nucleophile with either the secondary or quaternary carbon of the epoxy ring and these various modes of reaction of the spirocyclic system are discussed.The formation of ortho-substituted phenols from the 1-oxaspiroocta-5,7-dien-4-ones suggests that the latter structures may be regarded as polarity-reversed masked phenols.Tropolones, products of a possible ring-expansion reaction, were not observed in any of the reactions investigated.

2-[Alkyl substituted-phenoxy]-2,3-dihydro-1,2-benzoxaphosphole 2-oxide, cyclic phosphonates prepared, for example from hindered phenols and ortho-methylolphenols, are effective heat stabilizers and antioxidants for organic materials subject to degradation