Just add water to improve the performance of direct aldol reactions like that shown. Previously, aldehydes with high water-affinity or -solubility were considered unsuitable for asymmetric synthesis.

We have investigated by first principles the electronic, vibrational, and structural properties of bct C4, a new form crystalline sp{3} carbon recently found in molecular dynamics simulations nanotubes under pressure. This phase is transparent, dynamically stable at zero pressure, more than graphite beyond 18.6 GPa. Coexistence C4 with M can explain better x-ray diffraction pattern transparent hard produced cold compression graphite. Its structure appears to be intermediate between that...

Proper design of acid-base catalysis has been shown to be effective for achieving high reactivity and selectivity in the asymmetric direct aldol reaction during development diamine-Brønsted acid types catalyst. In this study, two principal approaches have implemented create a new type catalytic efficiency: one is creation highly viable acidic function within catalysts; other rather complicated but more cooperatively arranged hydrogen-bond networks that would expected stabilize transition...

Ironing it out: The straightforward N-alkylation using alcohols and iron/amino acid catalysis is described (see scheme). reaction does not proceed by the conventional "borrowing hydrogen" mechanism, but appears to involve a substitution pathway (SN) at sp3 carbon atom bearing hydroxy group of alcohol. Developing catalyst that effective near neutral pH was key successful N-alkylation. Detailed facts importance specialist readers are published as "Supporting Information". Such documents...

We report total-energy electronic structure calculations that provide energetics of encapsulation C60 in the carbon nanotube and structures resulting peapods. find encapsulating process is exothermic for (10,10) nanotube, whereas processes are endothermic (8,8) (9,9) nanotubes, indicative minimum radius 6.4 A. also C(60)@(10,10) a metal with multicarriers each which distributes either along or on chain. This unusual feature due to nearly free electron state inherent hierarchical solids...

As electronic devices and integrated circuits get smaller smaller, eventually quantum-mechanic effects take over. Saito discusses in his Perspective, results reported by Collins et al. the same issue demonstrate use of carbon nanotubes to create nanometer-scale known as diodes. Rather than fighting quantum mechanics, such make excellent on nanometer scale.

A novel catalyst system based on complexes of calcium which promote the catalytic asymmetric 1,4-addition reactions and [3+2] cycloaddition α-amino acid derivatives with α,β-unsaturated carbonyl compounds have been developed. The proceeded smoothly in presence 5−10 mol % chiral to afford desired adducts high yields diastereo- enantioselectivities. wide range esters amides were applicable, other glycine even dl-alanine reacted several corresponding substituted pyrrolodine excellent In...

Catalytic asymmetric 1,4-addition and [3 + 2] cycloaddition reactions using chiral calcium species prepared from isopropoxide bisoxazoline ligands have been developed. Glycine Schiff bases reacted with acrylic esters to afford products, glutamic acid derivatives, in high yields enantioselectivities. During the investigation of reactions, we unexpectedly found that a occurred crotonate affording substituted pyrrolidine derivatives On basis this finding, investigated cycloadditions, it was...

We investigate nitrogen-doping effects in a graphene sheet using first-principles electronic-structure study the framework of density-functional theory. As possible configurations nitrogen impurities graphene, substitutional and pyridine-type defects around monovacancy divacancy are considered, their energetics electronic structures discussed. The formation-energy calculations suggest that doping atom into is energetically most favorable among configurations. Furthermore, by comparison total...

New scoop on scope and selectivity: The hydration of organonitriles catalyzed by a RhI(OMe) species under nearly pH-neutral ambient conditions (25 °C, 1 atm) is chemoselective high-yielding (93 to 99 %), has broad substrate scope, may thus be complementary enzymatic methods for the introduction terminal amido group (CONH2) onto carbon chain.

Nanotubes reveal their potential: The fabrication of a thin film that retains isolated single-walled nanotubes (SWNTs) allows the experimental determination redox potentials many individual SWNTs have different chirality indexes (n,m). method is simple and applicable to all whose near-IR photoluminescence (PL) detectable (see picture). Detailed facts importance specialist readers are published as "Supporting Information". Such documents peer-reviewed, but not copy-edited or typeset. They...

A highly efficient tetradentate PNNP-type Ir photocatalyst, Mes-IrPCY2, was developed for the reduction of carbon dioxide. The photocatalyst furnished formic acid (HCO2H) with 87% selectivity together monoxide to achieve a turnover number 2560, which is highest among CO2 photocatalysts without an additional photosensitizer. Mes-IrPCY2 exhibited outstanding photocatalytic activity in presence sacrificial electron source 1,3-dimethyl-2-phenyl-2,3-dihydro-1H-benzo[d]imidazole (BIH)...

N-Methylation of amines with methanol proceeds at room temperature in the presence a silver-loaded titanium dioxide (Ag/TiO2) photocatalyst under UV-vis light irradiation. This method allows facile synthesis/isolation N-methylamines bearing various functional groups including N-benzyl, N-allyl, N-Boc, hydroxyl, ether, acetal, carboxamide, formamide, and olefin groups.

A virtually salt-free and straightforward bimolecular assembly giving N-unsubstituted pyrroles through fully unmasked α-amino aldehydes, which was enabled by the dual effects of a catalytic ruthenium complex an alkali metal base, is reported. Either solvent-free or acceptorless dehydrogenation facilitates high atom, step, pot economy, are otherwise difficult to achieve in multistep operations involving protection/deprotection.

Tetrakis(dimethylamido)diboron and tetrahydroxydiboron are herein reported as new catalysts for the synthesis of aryl amides by catalytic condensation aromatic carboxylic acids with amines. The developed protocol is both simple highly efficient over a broad range substrates. This method thus represents an attractive approach use diboron in without having to resort stoichiometric or additional dehydrating agents.

The photocatalytic reduction of carbon dioxide (CO

In nature, plants convert solar energy into chemical via water oxidation. Inspired by natural photosynthesis, artificial photosynthesis has been gaining increasing interest in the field of sustainability/green science and technology as a non-natural thermodynamically endergonic (ΔG° > 0, uphill) solar-energy-driven reaction that uses an electron donor source material. Among artificial-photosynthesis processes, inorganic-synthesis reactions oxidation, including splitting CO2-to-fuel...

The approach using pyrrolidine enamine as substrate has been studied for this synthesis, and an important catalyst structural feature developed. After survey of pyrrolidine-based Brønsted acid catalyst, tetrazole (3f) was found to be optimal in synthesis aminooxy carbonyl compounds high yields, with complete enantioselectivity not only aldehydes but also ketones.

Barium phenoxide-catalyzed, highly anti-selective direct-type aldol reactions of amides with aldehydes have been developed. In the presence a slight excess amount an amide, desired proceeded smoothly under mild conditions, and wide range aromatic, heterocyclic, α,β-unsaturated were applicable to afford adducts in high yields anti-selectivities. A catalytic, enantioselective reaction amide aldehyde using chiral ligand is also described.

Catalytic asymmetric hetero Diels−Alder (HDA) reactions using a chiral zirconium complex have been developed. The of aldehydes with Danishefsky's dienes proceeded smoothly to afford the corresponding pyranone derivatives in high yields diastereo- and enantioselectivities presence complex, which was prepared from tert-butoxide, (R)-3,3'-diiodobinaphthol or its derivative, primary alcohol, small amount water. It is noted that 2,3-trans-pyranone were obtained remarkably reaction 4-methyl diene....

A cross-coupling reaction of different alcohols was achieved using a pincer-type NHC/PdBr complex as the catalyst precursor, and reaction, under either Ar or H2 gas, displayed broad substrate scope with respect to both primary secondary alcohol components, high product selectivity.

Organic photoredox catalysts (OPCs) have the potential to replace precious-metal-based (PMPCs). Compared with strongly oxidizing OPCs, such as representative acridinium salts, however, recent development of reducing OPCs has been relatively sluggish. In this Perspective, bearing arylamine motifs are introduced. One advantages is their versatility in catalyst design, which makes it easier develop a capability superior that fac-[Ir(ppy)3], strongest reductant among commonly used PMPCs. Easy...