Why APRC is misleading and how it should be reformed

The annual percentage rate of charge (APRC) designed to reflect all costs of borrowing is a widely used measure to compare different credit products. It disregards completely, however, risks of possible future changes in interest and exchange rates. As an unintended consequence of the general advice to minimize APRC, many borrowers take adjustable-rate mortgages with extremely short interest rate period or foreign currency denominated loans and run into an excessive risk without really being aware of it. To avoid this, we propose a new, risk-adjusted APRC incorporating also the potential costs of risk hedging. This new measure eliminates most of the virtual advantages of riskier structures and reduces the danger of excessive risk taking. As an illustration, we present the latest Hungarian home loan trends but lessons are universal

Synthesis of Molybdenum and Tungsten Alkylidene Complexes that Contain a <i>tert</i>-Butylimido Ligand

A variety of molybdenum or tungsten complexes that contain a <i>tert</i>-butylimido ligand have been prepared. For example, the <i>o</i>-methoxybenzylidene complex W­(N-<i>t</i>-Bu)­(CH-<i>o</i>-MeOC₆H₄)­(Cl)₂(py) was prepared through addition of pyridinium chloride to W­(N-<i>t</i>-Bu)₂­(CH₂-<i>o</i>-MeOC₆H₄)₂, while Mo­(N-<i>t</i>-Bu)­(CH-<i>o</i>-MeOC₆H₄)­(OR_F)₂(<i>t</i>-BuNH₂) complexes (OR_F = OC₆F₅ or OC­(CF₃)₃) were prepared through addition of two equivalents of R_FOH to Mo­(N-<i>t</i>-Bu)₂­(CH₂-<i>o</i>-MeOC₆H₄)₂. An X-ray crystallographic study of Mo­(N-<i>t</i>-Bu)­(CH-<i>o</i>-MeOC₆H₄)­[OC­(CF₃)₃]₂­(<i>t</i>-BuNH₂) showed that the methoxy oxygen is bound to the metal and that two protons on the <i>tert</i>-butylamine ligand are only a short distance away from one of the CF₃ groups on one of the perfluoro-<i>tert</i>-butoxide ligands (H···F = 2.456(17) and 2.467(17) Å). Other synthesized tungsten <i>tert</i>-butylimido complexes include W­(N-<i>t</i>-Bu)­(CH-<i>o</i>-MeOC₆H₄)­(pyr)₂(2,2′-bipyridine) (pyr = pyrrolide), W­(N-<i>t</i>-Bu)­(CH-<i>o</i>-MeOC₆H₄)­(pyr)­(OHMT) (OHMT = O-2,6-(mesityl)₂C₆H₃), W­(N-<i>t</i>-Bu)­(CH-<i>t</i>-Bu)­(OHMT)­(Cl)­(py) (py = pyridine), W­(N-<i>t</i>-Bu)­(CH-<i>t</i>-Bu)­(OHMT)­(Cl), W­(N-<i>t</i>-Bu)­(CH-<i>t</i>-Bu)­(pyr)­(ODFT)­(py), W­(N-<i>t</i>-Bu)­(CH-<i>t</i>-Bu)­(OHMT)₂, and W­(N-<i>t</i>-Bu)­(CH-<i>t</i>-Bu)­(ODFT)₂ (ODFT = O-2,6-(C₆F₅)₂C₆H₃). Interestingly, W­(N-<i>t</i>-Bu)­(CH-<i>t</i>-Bu)­(OHMT)₂ does not react with ethylene or 2,3-dicarbomethoxynorbornadiene. Removal of pyridine from W­(N-<i>t</i>-Bu)­(CH-<i>t</i>-Bu)­(Biphen_CF3)­(pyridine) (Biphen_CF3 = 3,3′-di-<i>tert</i>-butyl-5,5′-bistrifluoromethyl-6,6′-dimethyl-1,1′-biphenyl-2,2′-diolate) with B­(C₆F₅)₃ led to formation of a five-coordinate 14<i>e</i> neopentyl complex as a consequence of CH activation in one of the methyl groups in one <i>tert</i>-butyl group of the Biphen_CF3 ligand, as was proven in an X-ray study. An attempted synthesis of W­(N-<i>t</i>-Bu)­(CH-<i>t</i>-Bu)­(Biphen_Me) (Biphen_Me = 3,3′-di-<i>tert</i>-butyl-5,5′,6,6′-tetramethyl-1,1′-biphenyl-2,2′-diolate) led to formation of a 1:1 mixture of W­(N-<i>t</i>-Bu)­(CH-<i>t</i>-Bu)­(Biphen_Me) and a neopentyl complex analogous to the one characterized through an X-ray study. The metallacyclobutane complexes W­(N-<i>t</i>-Bu)­(C₃H₆)­(pyrrolide)­(ODFT) and W­(N-<i>t</i>-Bu)­(C₃H₆)­(ODFT)₂ were prepared in reactions involving W­(N-<i>t</i>-Bu)­(CH-<i>t</i>-Bu)­(pyr)₂(bipy), ZnCl₂(dioxane), and one or two equivalents of DFTOH, respectively, under 1 atm of ethylene

Nickel Hydroxo Complexes as Intermediates in Nickel-Catalyzed Suzuki–Miyaura Cross-Coupling

The synthesis, characterization, and reactivity of intermediates formed in the Ni-catalyzed Suzuki–Miyaura cross-coupling (SMC) of an aryl chloride are described. Oxidative addition of 1-chloro-4-trifluoromethylbenzene (<b>1</b>) to a mixture of Ni­(cod)₂ and PCy₃ afforded NiCl­(4-CF₃Ph)­(PCy₃)₂ (<b>2</b>), which then cleanly provided dimeric [Ni­(4-CF₃Ph)­(μ–OH)­(PCy₃)]₂ (<b>3</b>) by reaction with aqueous KOH. Reactivity studies of <b>2</b> and <b>3</b> with phenylboronic acid (<b>4</b>) revealed that, while <b>2</b> affords only traces of the biphenyl coupling product after 24 h, the same reaction with <b>3</b> is complete within minutes at room temperature. In contrast, the reaction of <b>3</b> with potassium phenyltrihydroxyborate (<b>6</b>) is much slower than that with boronic acid <b>4</b>, and significantly lower yields of the cross-coupling product are obtained. We show that formation of the hydroxo species <b>3</b> is the rate-determining step in the present SMC

Nickel Hydroxo Complexes as Intermediates in Nickel-Catalyzed Suzuki–Miyaura Cross-Coupling

The synthesis, characterization, and reactivity of intermediates formed in the Ni-catalyzed Suzuki–Miyaura cross-coupling (SMC) of an aryl chloride are described. Oxidative addition of 1-chloro-4-trifluoromethylbenzene (<b>1</b>) to a mixture of Ni­(cod)₂ and PCy₃ afforded NiCl­(4-CF₃Ph)­(PCy₃)₂ (<b>2</b>), which then cleanly provided dimeric [Ni­(4-CF₃Ph)­(μ–OH)­(PCy₃)]₂ (<b>3</b>) by reaction with aqueous KOH. Reactivity studies of <b>2</b> and <b>3</b> with phenylboronic acid (<b>4</b>) revealed that, while <b>2</b> affords only traces of the biphenyl coupling product after 24 h, the same reaction with <b>3</b> is complete within minutes at room temperature. In contrast, the reaction of <b>3</b> with potassium phenyltrihydroxyborate (<b>6</b>) is much slower than that with boronic acid <b>4</b>, and significantly lower yields of the cross-coupling product are obtained. We show that formation of the hydroxo species <b>3</b> is the rate-determining step in the present SMC

Difference in the Reactivities of H- and Me-Substituted Dinucleating Bis(iminopyridine) Ligands with Nickel(0)

The reactivity of dinucleating bis­(iminopyridine) ligands bearing H (L¹, (<i>N</i>,<i>N</i>′)-1,1′-(1,4-phenylene)­bis­(<i>N</i>-(pyridin-2-ylmethylene)­methanamine)) or Me substituents (L², (<i>N</i>,<i>N</i>′)-1,1′-(1,4-phenylene)­bis­(<i>N</i>-(1-(pyridin-2-yl)­ethylidene)­methanamine)) on the imine carbon atom with Ni­(COD)₂ (COD = 1,5-cyclooctadiene) has been investigated. Treatment of L¹ with 2 equiv of Ni­(COD)₂ forms dinuclear Ni₂(L¹)­(COD)₂, whereas the reaction of L² with 2 equiv of Ni­(COD)₂ leads to Ni₂(L²)₂, along with 1 equiv of Ni­(COD)₂. The compounds were characterized by ¹H and ¹³C NMR spectroscopy, mass spectrometry, and elemental analysis; the structure of Ni₂(L²)₂ was determined by XRD. Ni₂(L²)₂ exists as syn and anti stereoisomers in the solid state and in solution. DFT calculations suggest Ni­(I) for both Ni₂(L¹)­(COD)₂ and Ni₂(L²)₂, with the radical anion localized on one iminopyridine fragment in Ni₂(L¹)­(COD)₂ and delocalized over two iminopyridine fragments in Ni₂(L²)₂. Both Ni₂(L¹)­(COD)₂ and Ni₂(L²)₂ undergo a reaction with excess diphenylacetylene, forming diphenylacetylene complexes. However, whereas Ni₂(L¹)­(diphenylacetylene)₂ decomposes upon removal of the excess diphenylacetylene, Ni₂(L²)₂ demonstrates a reversible disassembly/reassembly sequence upon the addition/removal of diphenylacetylene

Molybdenum and Tungsten Alkylidene and Metallacyclobutane Complexes That Contain a Dianionic Biphenolate Pincer Ligand

Molybdenum imido alkylidene and tungsten oxo alkylidene complexes that contain a tridentate “pincer” [ONO]^2– ligand have been prepared and treated with ethylene to give unsubstituted metallacyclobutane complexes that have a 16e count. Both Mo and W metallacyclobutane complexes exchange C₂D₄ into the metallacyclobutane ring at 22 °C at a rate that is first order in metal and zero order in C₂D₄. These metallacycles lose ethylene at least 10⁴–10⁵ times slower than reported 14e unsubstituted Mo and W metallacyclobutane complexes that have been explored in the literature that have a TBP geometry with the metallacyclobutane ring bound in the equatorial positions. Our studies suggest that breaking up the metallacyclobutane ring in these 16e d⁰ Mo or W complexes is slow because a 14e TBP metallacyclobutane complex cannot be accessed readily

Molybdenum and Tungsten Monoalkoxide Pyrrolide (MAP) Alkylidene Complexes That Contain a 2,6-Dimesitylphenylimido Ligand

Molybdenum and tungsten bispyrrolide alkylidene complexes that contain a 2,6-dimesitylphenylimido (NAr*) ligand have been prepared, in which the pyrrolide is the parent pyrrolide or 2,5-dimethylpyrrolide. Monoalkoxide pyrrolide (MAP) complexes were prepared through addition of 1 equiv of an alcohol to the bispyrrolide complexes. MAP compounds that contain the parent pyrrolide (NC₄H₄^–) are pyridine adducts, while those that contain 2,5-dimethylpyrrolide are pyridine free. Molybdenum and tungsten MAP 2,5-dimethylpyrrolide complexes that contain O-t-Bu, OCMe­(CF₃)₂, or O-2,6-Me₂C₆H₃ ligands were found to have approximately equal amounts of <i>syn</i> and <i>anti</i> alkylidene isomers, which allowed a study of the interconversion of the two employing ¹H–¹H EXSY methods. The <i>K</i>_eq values ([<i>syn</i>]/[<i>anti</i>]) are all 2–3 orders of magnitude smaller than those observed for a large number of Mo bisalkoxide imido alkylidene complexes, as a consequence of the destabilization of the <i>syn</i> isomer by the sterically demanding NAr* ligand. The rates of interconversion of <i>syn</i> and <i>anti</i> isomers were found to be 1–2 orders of magnitude faster for W MAP complexes than for Mo MAP complexes

Molybdenum and Tungsten Alkylidene and Metallacyclobutane Complexes That Contain a Dianionic Biphenolate Pincer Ligand

Molybdenum imido alkylidene and tungsten oxo alkylidene complexes that contain a tridentate “pincer” [ONO]^2– ligand have been prepared and treated with ethylene to give unsubstituted metallacyclobutane complexes that have a 16e count. Both Mo and W metallacyclobutane complexes exchange C₂D₄ into the metallacyclobutane ring at 22 °C at a rate that is first order in metal and zero order in C₂D₄. These metallacycles lose ethylene at least 10⁴–10⁵ times slower than reported 14e unsubstituted Mo and W metallacyclobutane complexes that have been explored in the literature that have a TBP geometry with the metallacyclobutane ring bound in the equatorial positions. Our studies suggest that breaking up the metallacyclobutane ring in these 16e d⁰ Mo or W complexes is slow because a 14e TBP metallacyclobutane complex cannot be accessed readily

Molybdenum and Tungsten Monoalkoxide Pyrrolide (MAP) Alkylidene Complexes That Contain a 2,6-Dimesitylphenylimido Ligand

Molybdenum and tungsten bispyrrolide alkylidene complexes that contain a 2,6-dimesitylphenylimido (NAr*) ligand have been prepared, in which the pyrrolide is the parent pyrrolide or 2,5-dimethylpyrrolide. Monoalkoxide pyrrolide (MAP) complexes were prepared through addition of 1 equiv of an alcohol to the bispyrrolide complexes. MAP compounds that contain the parent pyrrolide (NC₄H₄^–) are pyridine adducts, while those that contain 2,5-dimethylpyrrolide are pyridine free. Molybdenum and tungsten MAP 2,5-dimethylpyrrolide complexes that contain O-t-Bu, OCMe­(CF₃)₂, or O-2,6-Me₂C₆H₃ ligands were found to have approximately equal amounts of <i>syn</i> and <i>anti</i> alkylidene isomers, which allowed a study of the interconversion of the two employing ¹H–¹H EXSY methods. The <i>K</i>_eq values ([<i>syn</i>]/[<i>anti</i>]) are all 2–3 orders of magnitude smaller than those observed for a large number of Mo bisalkoxide imido alkylidene complexes, as a consequence of the destabilization of the <i>syn</i> isomer by the sterically demanding NAr* ligand. The rates of interconversion of <i>syn</i> and <i>anti</i> isomers were found to be 1–2 orders of magnitude faster for W MAP complexes than for Mo MAP complexes

Reduction of Dinitrogen to Ammonia Catalyzed by Molybdenum Diamido Complexes

[Ar₂N₃]­Mo­(N)­(O-<i>t</i>-Bu), which contains the conformationally rigid pyridine-based diamido ligand, [2,6-(ArNCH₂)₂­NC₅H₃]^2– (Ar = 2,6-diisopropyl­phenyl), can be prepared from H₂[Ar₂N₃], butyllithium, and (<i>t</i>-BuO)₃Mo­(N). [Ar₂N₃]­Mo­(N)­(O-<i>t</i>-Bu) serves as a catalyst or precursor for the catalytic reduction of molecular nitrogen to ammonia in diethyl ether between −78 and 22 °C in a batchwise manner with CoCp*₂ as the electron source and Ph₂NH₂OTf as the proton source. Up to ∼10 equiv of ammonia can be formed per Mo with a maximum efficiency in electrons of ∼43%