Katsuhiro Isozaki

Zap the jello: Stable solutions of a palladium-complexed dipeptide undergo gelation after brief ultrasound irradiation. This is the first case of a reversible, remotely controlled, and rapid sol–gel transition by H-bonding aggregates. By adjusting the sonication time, the gelation rates and heat-resistant properties of the aggregates can be controlled.

An unprecedented substrate-selective catalytic enhancement effect of an alkanethiol-self-assembled monolayer (SAM) on Au nanoparticles (AuNPs) is reported. In the supported 2D-array of AuNPs, the alkanethiol-SAM acts as a protein-like soft reaction space in which the substrate molecules are encapsulated through non-covalent intermolecular hydrophobic interactions, and thus catalytic reactions are accelerated at AuNP surfaces.

High-yielding cross-coupling reactions of various combinations of aryl chlorides and alkyl Grignard reagents have been developed by using an iron(III) fluoride/1,3-bis(2,6-diisopropylphenyl)imidazolin-2-ylidene (SIPr) catalyst composite. The iron(III) fluoride/SIPr-catalyzed aryl–alkyl coupling demonstrates unprecedented scope for both aryl chlorides and alkyl Grignard reagents, thus enabling the first efficient coupling of electron-rich (deactivated) aryl chlorides with alkyl Grignard­ reagents

Einmal durchgezappt: Stabile Lösungen eines palladiumkomplexierten Dipeptids gelieren nach einer kurzen Ultraschallbehandlung. Das ist der erste Fall eines reversiblen, ferngesteuerten und schnellen Sol-Gel-Übergangs bei wasserstoffverbrückten Aggregaten. Über die Dauer der Beschallung lassen sich die Gelierungsgeschwindigkeit und die Hitzebeständigkeit der Aggregate steuern. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2001/2007/z6050

Thiolate-protected gold nanoclusters (AuNCs) have attracted significant attention as nano-catalysts, revealing a superatomic core and gold-thiolate staples as distinct structural units. Here, we demonstrate the unprecedented dual catalytic activity of thiolate-protected [Au₂₅ (SR)₁₈ ]^- nanoclusters, involving both photosensitized ¹ O₂ generation by the Au₁₃ superatomic core and catalytic carbon-carbon bond formation facilitated by

Herein, we report the synthesis of gold nanoclusters (AuNCs) functionalized by peptide dendron thiolate ligands forming a hydrogen bonding supramolecular reaction field. The prepared AuNCs act as efficient photocatalysts that promote the oxidative cyclization of an amino alcohol to afford the oxazolidine product. Circular dichroism (CD) spectroscopy and 1H NMR titration experiments revealed that the dynamic transformation of interdendron hydrogen bonds into intermolecular hydrogen bonds between

Innovative nanophotonic applications require a technique for generating not a nanometer-scale point but a large-area (mm2−m2) near-field light source. We succeeded in developing a large-area near-field light source that is densely constructed of uniform-size gold nanoparticles (AuNPs) two-dimensionally arrayed with regular interparticle gaps, which has tunable localized surface plasmon resonance bands (600–1100 nm). The near-field excitation properties based on the optical tunability of the AuNP

Pd- and Pt-bound bis-metalated peptides were synthesised by the condensation of Pd- or Pt-aldimine-complex-bound glutamic acids to afford the four possible metal isomers of bis-Pd and bis-Pt-homometalated dipeptides and PdPt- and PtPd-heterometalated dipeptides without metal disproportionation. Ultrasound-induced self-assembly of these bis-metalated peptides proceeded effectively to afford supramolecular gels that displayed well-ordered metal arrays. The formation of parallel β-sheet type aggreg

The first iron-catalysed cross coupling of propargyl electrophiles with lithium alkenylborates has been developed. Various propargyl electrophiles can be cross-coupled with lithium (E)- or (Z)-alkenylborates in a stereospecific manner to afford the corresponding 1,4-enynes in good to excellent yields. The reaction features high SN2-type regioselectivity and functional group compatibility.

A new type of Pt-complex-bound amino acid was synthesized by condensation of a cyclometalated Pt complex with the side-chain residue of N- and C-alkylated glutamic acid. Self-assembly of the Pt-bound lipophilic amino acid afforded a supramolecular gel in organic solvents, which comprised fibrous lamellar aggregates that supported a highly oriented Pt array.

Exploration of multiple bonds between superatoms remains an uncharted territory. In this study, we present the synthesis and characterization of N₂-type superatomic molecules featuring triple bonds between two superatoms. The successful synthesis of M₂Au₁₇ (M = Pd, Pt) nanoclusters hinged upon the photoinduced fusion of MAu₁₂ superatoms, achieved through sequential electron transfer and detachment of [AuPR₃]⁺ species. Solid-state

A Ru-bound norvaline shows enhanced catalytic activity for the oxidation of methoxybenzenes with unique chemoselectivity.

Iron oxide nanoparticles (NPs) are nontoxic and abundant materials which have long been investigated as reusable catalysts in oxidation reactions, but their use so far has been hampered by a low selectivity. Here, unsupported iron oxide NPs have been found to successfully catalyze the microwave-assisted oxidation of primary and secondary alcohols to their respective aldehydes and ketones with a high selectivity when <i>N</i>-methylmorpholine <i>N</i>-oxide was used as the terminal oxidant. The c

A PCP pincer palladium-complex-bound norvaline, Boc-<sc>l</sc>-[Pd]Nva-OMe, was synthesized and fully characterized by NMR, FT-ICR-MS, and X-ray crystallography. Selective N- and C-terminus transformations of Boc-<sc>l</sc>-[Pd]Nva-OMe were performed by conventional deprotection–condensation procedures to afford lipophilic palladium-bound norvaline derivatives without metal detachment. The N-/C-bisfunctionalized palladium-bound norvaline showed self-assembly properties, as evidenced by supramole