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The pathogenic bacterium Staphylococcus aureus can penetrate host cells. However, intracellular S. aureus is not considered during antimicrobial agent selection in clinical chemotherapy because of the lack of information about drug transportability into cells in vivo. We focused on agents used to treat methicillin-resistant S. aureus (MRSA) (vancomycin, arbekacin, linezolid, and daptomycin) and indirectly assessed the drug levels in intracellular compartment using plasma, tissue homogenates, and interstitial fluid (ISF) samples from the skin of rats using the microneedle array technique. Lower drug levels were observed in the ISF than in the plasma for daptomycin but extracellular and intracellular drug levels were comparable. In contrast, vancomycin, arbekacin, and linezolid showed higher concentrations in the ISF than in the plasma. Intracellular transport was estimated only for arbekacin. Stasis of vancomycin in the ISF was also observed. These results suggest that both low vancomycin exposure against intracellular S. aureus infection and long-term subinhibitory drug levels in the ISF contribute to the failure of treatment and emergence of antibiotic resistance. Based on its pharmacokinetic characteristics in niche extravascular tissue spaces, arbekacin may be suitable for achieving sufficient clinical outcomes for MRSA infection because the drug is widely distributed in extracellular and intracellular compartments.

Heterogeneously catalysed synthesis of primary amines by direct amination of alcohols with ammonia has long been an elusive goal. In contrast to reported Ru-based catalytic systems, we report that Ru–MgO/TiO2 acts as an effective heterogeneous catalyst for the direct amination of a variety of alcohols to primary amines at low temperatures of ca. 100 °C without the introduction of H2 gas. The present system could be applied to a variety of alcohols and provides an efficient synthetic route for 2,5-bis(aminomethyl)furan (BAMF), an attention-getting biomonomer. The high catalytic performance can be rationalized by the reactivity tuning of Ru–H species using MgO. Spectroscopic measurements suggest that MgO enhances the reactivity of hydride species by electron donation from MgO to Ru., Ru–MgO/TiO2 exhibited high catalytic performance for direct amination of alcohols based on the acceleration effects of MgO.

High-surface-area β-MnO2 (β-MnO2-HS) nanoparticles could act as effective heterogeneous catalysts for the one-pot oxidative sulfonamidation of various aromatic and heteroaromatic thiols to the corresponding sulfonamides using molecular oxygen (O2) and ammonia (NH3) as respective oxygen and nitrogen sources, without the need for any additives.

The local structure on the surface of plate-like cellulose II oligomer crystals (CIIOCs) was investigated by NMR spectroscopy. CIIOCs with reducing ends that were selectively labeled with 13C were enzymatically synthesized using cellodextrin phosphorylase. The solid-state 13C cross polarization/magic angle spinning spectra of the 13C-labeled CIIOCs clearly exhibited two resonance peaks (labeled as C1Rα and C1Rβ) derived from the C1 atoms of the reducing ends. The 2D 13C double quantum/13C single quantum homonuclear correlation spectrum indicated that two magnetically nonequivalent glucopyranose rings (Rα and Rβ units) coexisted at the reducing end units. The 1H/13C heteronuclear correlation spectrum suggested that there was a large difference between the local environments around the anomeric carbons of Rα and Rβ units. The abundance ratio of C1Rβ to C1Rα in the solid state was 4:1, whereas that of C1α and C1β in solution was 1:1. When the oligomer chains are packed in the cellulose II crystal, the reducing end units located on the surface of the plate-like crystal may tend to have β-anomeric structure, which would be more sterically stable than the α-anomeric structure.

Highly selective synthesis of primary amines over heterogeneous catalysts is still a challenge for the chemical industry. Ruthenium nanoparticles supported on Nb2O5 act as a highly selective and reusable heterogeneous catalyst for the low-temperature reductive amination of various carbonyl compounds that contain reduction-sensitive functional groups such as heterocycles and halogens with NH3 and H2 and prevent the formation of secondary amines and undesired hydrogenated byproducts. The selective catalysis of these materials is likely attributable to the weak electron-donating capability of Ru particles on the Nb2O5 surface. The combination of this catalyst and homogeneous Ru systems was used to synthesize 2,5-bis(aminomethyl)furan, a monomer for aramid production, from 5-(hydroxymethyl)furfural without a complex mixture of imine byproducts.

A CePO4 catalyst exhibits high catalytic performance for the chemoselective acetalization of 5-hydroxymethylfurfural with alcohols, in sharp contrast to other homogeneous and heterogeneous acid and/or base catalysts., Acid–base solid catalysts synthesized with structurally controlled uniform active sites can lead to unique catalysis. In this study, a CePO4 catalyst was synthesized using a hydrothermal method and found to exhibit high catalytic performance for the chemoselective acetalization of 5-hydroxymethylfurfural with alcohols, in sharp contrast to other homogeneous and heterogeneous acid and/or base catalysts. In the presence of CePO4, various combinations of carbonyl compounds and alcohols are efficiently converted into the corresponding acetal derivatives in good to excellent yields. Mechanistic studies show that CePO4 most likely acts as a bifunctional catalyst through the interaction of uniform Lewis acid and weak base sites with 5-hydroxymethylfurfural and alcohol molecules, respectively, which results in high catalytic performance.

A catalyst system of manganese with 2,2-bipyridine for amide alcoholysis of N-β-hydroxyethylamides is described. This protocol enabled selective cleavage of the amide bond through a mechanism involving sequential N,O-acyl rearrangement and transesterification.

Asymmetric hydrogenation of 1- and 3-substituted and 1,3-disubstituted isoquinolinium chlorides using triply halide-bridged dinuclear iridium complexes [{Ir(H)(diphosphine)}2 (μ-Cl)3 ]Cl has been achieved by the strategy of HCl salt formation of isoquinolines to afford the corresponding chiral 1,2,3,4-tetrahydroisoquinolines (THIQs) in high yields and with excellent enantioselectivities after simple basic work-up. The effects of salt formation have been investigated by time-course experiments, which revealed that the generation of isoquinolinium chlorides clearly prevented formation of the catalytically inactive dinuclear trihydride complex, which was readily generated in the catalytic reduction of salt-free isoquinoline substrates. Based on mechanistic investigations, including by (1) H and (31) P{(1) H} NMR studies and the isolation and characterization of several intermediates, the function of the chloride anion of the isoquinolinium chlorides has been elucidated, allowing us to propose a new outer-sphere mechanism involving coordination of the chloride anion of the substrates to an iridium dihydride species along with a hydrogen bond between the chloride ligand and the N-H proton of the substrate salt.

Benzylic C H fluorination is the straightforward method for the synthesis of fluoromethylarenes, which are utilized as oxygen mimics in molecules such as nucleotides, phosphate esters and sulfate esters. We reveal that silver particles supported on a metal oxide act as an efficient catalyst for the benzylic C H fluorination of 4-methylbiphenyl with 1-fluoro-4-methyl-1,3-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate) (Selectfluor II) as a fluorinating reagent to give 4-(fluoromethyl)-1,1′-biphenyl, whereas silver oxides resulted in aromatic fluorination. Among the catalysts tested, Ag/SiO2 exhibited the highest activity for fluorination to give the fluorinated product in 75% yield. This system was applicable to larger-scale fluorination. Mechanistic studies revealed that the present fluorination likely involves single electron transfer (SET) processes between Ag particles and 4-methylbiphenyl to afford radical species.

In the presence of a chiral iridium catalyst, 1- and 3-substituted as well as 1,3-disubstituted isoquinolinium salts can be hydrogenated, giving the corresponding 1,2,3,4-tetrahydroisoquinolines in high enantiomeric excess.

Efficient rhodium(III) catalysts were developed for asymmetric hydrogenation of simple olefins. A new series of chloride-bridged dinuclear rhodium(III) complexes 1 were synthesized from the rhodium(I) precursor [RhCl(cod)]2 , chiral diphosphine ligands, and hydrochloric acid. Complexes from the series acted as efficient catalysts for asymmetric hydrogenation of (E)-prop-1-ene-1,2-diyldibenzene and its derivatives without any directing groups, in sharp contrast to widely used rhodium(I) catalytic systems that require a directing group for high enantioselectivity. The catalytic system was applied to asymmetric hydrogenation of allylic alcohols, alkenylboranes, and unsaturated cyclic sulfones. Control experiments support the superiority of dinuclear rhodium(III) complexes 1 over typical rhodium(I) catalytic systems.

Iridium(III) complexes bearing chiral ligands have proved to be active species in asymmetric hydrogenation of C=N bonds, though there are only a few iridium(III) precursors. We prepared triply halide-bridged dinuclear iridium complexes bearing chiral diphosphine ligands by simple treatment of the iridium(I) precursor, chiral diphosphine, and aqueous hydrogen halide. The strong advantage of these dinuclear iridium complexes is that they are air and moisture stable, leading to easy handling in asymmetric synthesis. The dinuclear iridium complexes exhibited high catalytic activity toward asymmetric hydrogenation of imines and N-heteroaromatics. Moreover, we demonstrated the application of triply halide-bridged dinuclear ruthenium(II) and rhodium(III) catalyst precursors for the asymmetric hydrogenation of ketonic substrates and simple olefins, respectively.

Efficient rhodium(III) catalysts were developed for asymmetric hydrogenation of simple olefins. A new series of chloride-bridged dinuclear rhodium(III) complexes 1 were synthesized from the rhodium(I) precursor [RhCl(cod)]2 , chiral diphosphine ligands, and hydrochloric acid. Complexes from the series acted as efficient catalysts for asymmetric hydrogenation of (E)-prop-1-ene-1,2-diyldibenzene and its derivatives without any directing groups, in sharp contrast to widely used rhodium(I) catalytic systems that require a directing group for high enantioselectivity. The catalytic system was applied to asymmetric hydrogenation of allylic alcohols, alkenylboranes, and unsaturated cyclic sulfones. Control experiments support the superiority of dinuclear rhodium(III) complexes 1 over typical rhodium(I) catalytic systems.

A rhodium-catalyzed coupling reaction of 2-trimethylsilylphenylboronic acid with internal alkynes is developed for the synthesis of 2,3-disubstituted benzosilole derivatives. A range of functional groups, encompassing ketones, esters, amines, aryl bromides, and heteroarenes, are compatible, which provides rapid access to diverse benzosiloles. Sequential 2-fold coupling enables modular synthesis of asymmetrically substituted 1,5-dihydro-1,5-disila-s-indacene, a π-extended molecule of interest in organic electronics. In terms of the mechanism, the reaction involves cleavage of a C(alkyl)-Si bond in a trialkylsilyl group, which normally requires extremely harsh conditions for activation. Mechanistic studies, including effects of substituents, reveal that C-Si bond cleavage does not proceed through a hypercoordinated silicon species, but rather through a rhodium-mediated activation process. The potential use of the reaction in catalytic asymmetric synthesis of Si-chiral benzosiloles is also demonstrated.

The additive effects of amines were realized in the asymmetric hydrogenation of 2-phenylquinoxaline, and its derivatives, catalyzed by chiral cationic dinuclear triply halide-bridged iridium complexes [{Ir(H)[diphosphine]}(2)(μ-X)(3)]X (diphosphine = (S)-2,2'-bis(diphenylphosphino)-1,1'-binaphthyl [(S)-BINAP], (S)-5,5'-bis(diphenylphosphino)-4,4'-bi-1,3-benzodioxole [(S)-SEGPHOS], (S)-5,5'-bis(diphenylphosphino)-2,2,2',2'-tetrafluoro-4,4'-bi-1,3-benzodioxole [(S)-DIFLUORPHOS]; X = Cl, Br, I) to produce the corresponding 2-aryl-1,2,3,4-tetrahydroquinoxalines. The additive effects of amines were investigated by solution dynamics studies of iridium complexes in the presence of N-methyl-p-anisidine (MPA), which was determined to be the best amine additive for achievement of a high enantioselectivity of (S)-2-phenyl-1,2,3,4-tetrahydroquinoxaline, and by labeling experiments, which revealed a plausible mechanism comprised of two cycles. One catalytic cycle was less active and less enantioselective; it involved the substrate-coordinated mononuclear complex [IrHCl(2)(2-phenylquinoxaline){(S)-BINAP}], which afforded half-reduced product 3-phenyl-1,2-dihydroquinoxaline. A poorly enantioselective disproportionation of this half-reduced product afforded (S)-2-phenyl-1,2,3,4-tetrahydroquinoxaline. The other cycle involved a more active hydride-amide catalyst, derived from amine-coordinated mononuclear complex [IrCl(2)H(MPA){(S)-BINAP}], which functioned to reduce 2-phenylquinoxaline to (S)-2-phenyl-1,2,3,4-tetrahydroquinoxaline with high enantioselectivity. Based on the proposed mechanism, an Ir(I)-JOSIPHOS (JOSIPHOS = (R)-1-[(S(p))-2-(dicyclohexylphosphino)ferrocenylethyl]diphenylphosphine) catalyst in the presence of amine additive resulted in the highest enantioselectivity for the asymmetric hydrogenation of 2-phenylquinoxaline. Interestingly, the reaction rate and enantioselectivity were gradually increased during the reaction by a positive-feedback effect from the product amines.

A new rhodium-catalyzed method for preparing arylboronates from aryl cyanides through the cleavage of carbon–cyano bonds is described. This unprecedented transformation of nitriles allows the use of a cyano group as a boryl equivalent and the regioselective introduction of a boryl group at a late stage of the synthesis.

An efficient catalytic system of a zinc cluster and tetrabutylammonium iodide (TBAI) was developed for cyclic carbonate synthesis from epoxides and carbon dioxide (CO2) without the use of any organic solvents under very mild conditions (25 °C, 1 atm), even in the presence of impurities such as water and air. Electrophilicity of the central Zn(II) ion, the number of trifluoromethyl groups, nucleophilicity and leaving ability of the anion of alkylammonium salts, and various reaction parameters have a great effect on the catalytic activity of the bifunctional catalyst. Therefore, this solvent-free process represents an environmentally friendly example for the catalytic conversion of CO2 into value-added chemicals and also has the potential to contribute towards decreasing atmospheric CO2 emission from the burning of fossil fuels.

The reaction of aryl cyanides with diboron in the presence of a rhodium/Xantphos catalyst and DABCO affords arylboronic esters via carbon-cyano bond cleavage. This unprecedented mode of reactivity for a borylrhodium species allows the regioselective introduction of a boryl group in a late stage of synthesis.

A salt formation strategy for asymmetric hydrogenation of pyridines is described. Poly-substituted pyridinium salts were successfully hydrogenated using chiral iridium dinuclear complexes to afford...

Investigations reveal that the presence of a fluorine substituent is required for a successful cyclization.

Tsuda M., Terao K., Nakamura Y., et al. Solution properties of amylose tris(3,5-dimethylphenylcarbamate) and amylose tris(phenylcarbamate): Side group and solvent dependent chain stiffness in methyl acetate, 2-butanone, and 4-methyl-2-pentanone. Macromolecules, 43(13), 5779-5784, June 11, 2010. Copyright © 2010, American Chemical Society. https://doi.org/10.1021/ma1006528., Five amylose tris(3,5-dimethylphenylcarbamate) (ADMPC) samples ranging in weightaverage molecular weight M w from 1.7 × 10 4 to 3.4 × 10 5 were studied by light and small-angle X-ray scattering, sedimentation equilibrium, and viscometry in methyl acetate (MEA), 2-butanone (MEK), and 4-methyl-2-pentanone (MIBK) at 25 °. Seven amylose tris(phenylcarbamate) (ATPC) samples whose M w ranges between 2 × 10 4 and 3×10 6 were also investigated in MEK at 25 °. The radii of gyration, particle scattering functions, and intrinsic viscosities determined as a function of M w were analyzed in terms of the cylindrical wormlike chain model mainly to determine the Kuhn segment length λ -1 and the contour length h (or the helix pitch) per residue. While the obtained h values (0.36-0.38 nm) of ADMPC are quite insensitive to the solvents, the λ -1 value not only is 1.5-3 times larger than that of ATPC in the corresponding solvent but also significantly increases with an increase of the molar volume of the solvent, and it reaches 73 nm in MIBK, which is the highest value for previously investigated phenylcarbamate derivatives of polysaccharides. This high stiffness is most likely due to the steric hindrance of the solvent molecules H-bonding with the NH groups of the polymer. © 2010 American Chemical Society.

A rhodium-catalyzed reductive cleavage reaction of carbon-cyano bonds is developed using hydrosilane as a mild reduc-ing agent. A wide range of nitriles, including aryl, benzyl, and β-hydrogen containing alkyl cyanides are applicable to this decyanation reaction. The method is also applicable to organic synthesis, in which benzyl cyanide is used as a benzyl anion equivalent and a cyano group functions as a removable ortho-directing group.

コラーゲンモデルペプチドの一つである(Pro-Pro-Gly)5(以下 PPG5 と略す)が 10 mM の LiClO4 を含むメタノール中でポリアクリル酸(PAA)と複合体を形成することを見いだした．PPG5 の質量濃度を 3.23×10－5 g cm－3 とした場合，PAA と PPG5 のモル比 Cp/Cc が 0.06 と 0.3 のものについては濁りが見られたのに対し，Cp/Cc=3 の溶液は透明であり，動的光散乱測定からも巨大な会合体はほとんど存在しないことがわかった．この溶液および，PPG5 単独溶液について円二色性測定を行い，前者の三重らせん－1 本鎖の転移温度が後者よりも約 30 K 高いこと，すなわち，少量の PAA 鎖の存在によって，PPG5 の三重らせんが著しく安定化されることが見いだされた．さらに，この現象が PPG5 と PAA 間の解離会合平衡によって説明できることを示した．

Rhodium-catalyzed carbon-cyano bond cleavage reactions using organosilicon reagents are described. When disilane is used as the silicon reagent, the C-CN bonds in aryl and alkenyl cyanides are silylated to form the corresponding silylated products along with silyl cyanide. Reductive decyanation of nitriles is achieved when hydrosilane is used as the silicon reagent. In addition, this catalytic system can be applied to the C(sp3)-CN bonds in simple aliphatic nitriles. In both reactions, the silylrhodium species generated in situ serves as a catalytically active species, cleaving C-CN bonds via an η2-iminoacyl complex. Addition of external electrophiles allowed the silicon-assisted cleavage of C-CN bonds to be applied to C-C bond formation reactions. Intramolecular arylation of benzonitrile bearing a tethered chlorophenyl group and decyanative Mizoroki-Heck-type alkenylation of nitriles with vinylsilanes have been developed.

Small-angle X-ray scattering (SAXS), circular dichroism (CD), and density measurements were made on eight samples of collagen model peptides consisting of glycine (Gly), proline (Pro), and 4-(R)-hydroxyproline (Hyp), i.e., (Gly-Hyp-Hyp) n , (Gly-Pro-Hyp) n , (Gly-Hyp-Pro) n , and (Gly-Pro-Pro) n (n = 5 and 9) in pure water and in phosphate buffered saline at a wide range of temperatures between 4 and 75 °C. A complete triple-helical structure was found only for (Gly-Hyp-Hyp) 9 and (Gly-Pro-Hyp) 9 at 15 °C by SAXS and CD, and (Gly-Pro-Pro) 9 had a partially formed triple helix at 4 °C. At 70 °C or higher temperatures, all peptides are dispersed as monomeric chains in these solvents and have essentially the same radii of gyration as the literature values for denatured proteins with the equivalent number of amino acid residues, suggesting that the conformational entropy for the single chain of the collagen model peptides is almost independent of the imino acid content. Furthermore, the partial specific volume v for (Gly-Hyp-Hyp) 9 around the transition temperature decreases more gradually with decreasing temperature than that for (Gly-Hyp-Hyp) 5 . On the contrary, the temperature dependence of v for (Gly-Pro-Hyp) n has the opposite tendency, indicating that the hydration number for the peptide (Gly-Pro-Hyp) 9 increases with formation of the triple helix whereas that for the peptide (Gly-Hyp-Hyp) 9 decreases. These results are consistent with the difference in the transition enthalpies reported previously [J. Biol. Chem. 2004, 279, 38072].

The palladium-catalyzed decarboxylative allylic alkylation of enol carbonates derived from lactams and ketones is described. Employing these substrates with an electronically tuned Pd catalyst system trisubstituted chiral centers are produced. These stereocenters have been previously challenging to achieve using Pd complex/chiral P–N ligand systems.

International audience; Direct amination of allylic alcohols with primary and secondary amines catalyzed by a system made of [Ni(1,5-cyclooctadiene)2 ] and 1,1'-bis(diphenylphosphino)ferrocene was effectively enhanced by adding nBu4 NOAc and molecular sieves, affording the corresponding allyl amines in high yield with high monoallylation selectivity for primary amines and high regioselectivity for monosubstituted allylic alcohols. Such remarkable additive effects of nBu4 NOAc were elucidated by isolating and characterizing some nickel complexes, manifesting the key role of a charge neutral pentacoordinated η(3) -allyl acetate complex in the present system, in contrast to usual cationic tetracoordinated complexes earlier reported in allylic substitution reactions.

The palladium-catalyzed decarboxylative allylic alkylation of enol carbonates derived from lactams and ketones is described. Employing these substrates with an electronically tuned Pd catalyst system trisubstituted chiral centers are produced. These stereocenters have been previously challenging to achieve using Pd complex/chiral P–N ligand systems.

Asymmetric hydrogenation of quinazolinium salts was catalysed by halogen-bridged dinuclear iridium complexes bearing chiral diphosphine ligands, yielding tetrahydroquinazoline and 3,4-dihydroquinazoline with high enantioselectivity. A derivative of chiral dihydroquinazoline was used as a chiral NHC ligand.

Substituted pyridinium salts of type (I) and (III) undergo asymmetric hydrogenation when chiral iridium dinuclear complexes such as DFP are used as catalyst.

Unprecedented aryl-to-aryl 1,5-rhodium migration is involved in decyanative silylation of aryl cyanides bearing a tethered arene. The 1,5-migration proceeds through remote C–H bond activation. 1,5-Migration also occurs in other rhodium-catalyzed reactions, including borylation and oxidative Mizoroki–Heck reactions.

A new rhodium-catalyzed method for preparing arylboronates from aryl cyanides through the cleavage of carbon–cyano bonds is described. This unprecedented transformation of nitriles allows the use of a cyano group as a boryl equivalent and the regioselective introduction of a boryl group at a late stage of the synthesis.

Unprecedented aryl-to-aryl 1,5-rhodium migration is involved in decyanative silylation of aryl cyanides bearing a tethered arene. The 1,5-migration proceeds through remote C–H bond activation. 1,5-Migration also occurs in other rhodium-catalyzed reactions, including borylation and oxidative Mizoroki–Heck reactions.

The transformation of β-hydroxyethylamides, e.g. (I), (IV) or (VI), into carboxylic esters (II), (V) and (VII), resp., is efficiently achieved in the presence of Zn catalyst using ethyl carbonate to capture the released ethanolamine.

The reaction of epoxides (I) with carbon dioxide is smoothly catalyzed by a tetranuclear zinc cluster—tetrabutylammonium iodide system to afford cyclic carbonates (III) in excellent yields.

The transformation of β-hydroxyethylamides, e.g. (I), (IV) or (VI), into carboxylic esters (II), (V) and (VII), resp., is efficiently achieved in the presence of Zn catalyst using ethyl carbonate to capture the released ethanolamine.

Rhodium-catalyzed carbon-cyano bond cleavage reactions using organosilicon reagents are described. When disilane is used as the silicon reagent, the C-CN bonds in aryl and alkenyl cyanides are silylated to form the corresponding silylated products along with silyl cyanide. Reductive decyanation of nitriles is achieved when hydrosilane is used as the silicon reagent. In addition, this catalytic system can be applied to the C(sp3)-CN bonds in simple aliphatic nitriles. In both reactions, the silylrhodium species generated in situ serves as a catalytically active species, cleaving C-CN bonds via an η2-iminoacyl complex. Addition of external electrophiles allowed the silicon-assisted cleavage of C-CN bonds to be applied to C-C bond formation reactions. Intramolecular arylation of benzonitrile bearing a tethered chlorophenyl group and decyanative Mizoroki-Heck-type alkenylation of nitriles with vinylsilanes have been developed.

Investigations reveal that the presence of a fluorine substituent is required for a successful cyclization.

A wide range of aryl and heteroaryl nitriles is undergoing the reaction with triethylvinylsilane (II) to afford the mixtures of the alkenylated and silylated products (III) and (IV).

A rhodium-catalyzed reductive cleavage reaction of carbon-cyano bonds is developed using hydrosilane as a mild reduc-ing agent. A wide range of nitriles, including aryl, benzyl, and β-hydrogen containing alkyl cyanides are applicable to this decyanation reaction. The method is also applicable to organic synthesis, in which benzyl cyanide is used as a benzyl anion equivalent and a cyano group functions as a removable ortho-directing group.

The reaction of 2-(trimethylsilyl)phenylboronic acid with alkynes in the presence of a rhodium catalyst affords benzosilole derivatives. The arylvinylrhodium intermediate undergoes formal substitution at a silicon center, resulting in the cleavage of a robust silicon−methyl bond in the trimethylsilyl group.

The rhodium-catalyzed reductive cleavage of carbon−cyano bonds is developed using hydrosilane as a mild reducing agent. A wide range of nitriles, including aryl, benzyl, and β-hydrogen containing alkyl cyanides are applicable to this decyanation reaction. The method can also be applied to organic synthesis; the use of benzyl cyanide as a benzyl anion equivalent and the use of a cyano group as a removable ortho-directing group are demonstrated.

The reaction of 2-(trimethylsilyl)phenylboronic acid with alkynes in the presence of a rhodium catalyst affords benzosilole derivatives. The arylvinylrhodium intermediate undergoes formal substitution at a silicon center, resulting in the cleavage of a robust silicon−methyl bond in the trimethylsilyl group.

A rhodium-catalyzed silylation reaction of carbon−cyano bonds using disilane has been developed. Under these catalytic conditions, carbon−cyano bonds in aryl, alkenyl, allyl, and benzyl cyanides bearing a variety of functional groups can be silylated. The observation of an enamine side product in the silylation of benzyl cyanides and related stoichiometric studies indicate that the carbon−cyano bond cleavage proceeds through the deinsertion of silyl isocyanide from η2-iminoacyl complex B. Knowledge gained from these studies has led to the development of a new intramolecular biaryl coupling reaction in which aryl cyanides and aryl chlorides are cross-coupled.

A rhodium-catalyzed silylation reaction of carbon-cyano bonds using disilane has been developed. Under these catalytic conditions, carbon-cyano bonds in aryl, alkenyl, allyl, and benzyl cyanides bearing a variety of functional groups can be silylated. The observation of an enamine side product in the silylation of benzyl cyanides and related stoichiometric studies indicate that the carbon-cyano bond cleavage proceeds through the deinsertion of silyl isocyanide from eta(2)-iminoacyl complex B. Knowledge gained from these studies has led to the development of a new intramolecular biaryl coupling reaction in which aryl cyanides and aryl chlorides are cross-coupled.

The Rh(I)-catalyzed silylation of nitriles with disilanes is described. The cleavage of inert carbon−cyano and silicon−silicon bonds occurs in this catalysis.

The rhodium-catalyzed reductive cleavage of carbon-cyano bonds is developed using hydrosilane as a mild reducing agent. A wide range of nitriles, including aryl, benzyl, and beta-hydrogen containing alkyl cyanides are applicable to this decyanation reaction. The method can also be applied to organic synthesis; the use of benzyl cyanide as a benzyl anion equivalent and the use of a cyano group as a removable ortho-directing group are demonstrated.