Nickel-Catalyzed Cyanation of Allylic Alcohols: High Degree of Chiral Inversion in Aqueous Reaction Media.

Nickel-catalyzed aqueous cyanation of allylic alcohols is herein described. This catalytic protocol provided environmentally friendly and operationally simple access to a variety of allylic nitriles in good yields. For chiral allylic alcohols, the reaction gave chiral allylic nitriles with a high degree of chiral inversion.

Palladium-Catalyzed Hydrocyanation of Ynoates: En Route to the Stereodivergent Synthesis of β-Cyanated α,β-Unsaturated Esters via Ligand Controlled Regio- and Stereoselectivity.

A Pd-catalyzed highly regio- and stereoselective hydrocyanation was developed, providing a novel approach to the stereodivergent synthesis of β-cyano-substituted acrylates in good yields with a wide substrate scope. The judicious selection of ligands was crucial for elegant control over the stereodivergence. Furthermore, the success of the -hydrocyanation hinges on the right matching of Pd and , which not only ensured the catalytic activity but also prevented the formation of α-cyanation products.

/-Heteroleptic Cu(I)-Photosensitizer-Catalyzed [3 + 2] Regiospecific Annulation of Aminocyclopropanes and Functionalized Alkynes.

We report here a regiospecific [3 + 2] annulation between aminocyclopropanes and various functionalized alkynes enabled by a /-heteroleptic Cu(I) photosensitizer under photoredox catalysis conditions. Thus, a divergent construction of 3-aminocyclopentene derivatives including methylsulfonyl-, arylsulfonyl-, chloro-, ester-, and trifluoromethyl-functionalized aminocyclopentenes could be achieved with advantages of high regioselectivity, broad substrate compatibility, and mild and environmentally benign reaction conditions.

Single Cu(I)-Photosensitizer Enabling Combination of Energy-Transfer and Photoredox Catalysis for the Synthesis of Benzo[]fluorenols from 1,6-Enynes.

An efficient, mild, and atom-economical synthesis of benzo[]fluorenols from 1,6-enynes has been developed under photocatalytic conditions. A single P/N heteroleptic Cu(I)-photosensitizer might exhibit both energy-transfer and photoredox catalytic activities in the formation of benzo[]fluorenols.

Tertiary Amines Acting as Alkyl Radical Equivalents Enabled by a P/N Heteroleptic Cu(I) Photosensitizer.

An unprecedented exploration of tertiary amines as alkyl radical equivalents for cross-coupling with aromatic alkynes to access allylarenes has been achieved by a P/N heteroleptic Cu(I)-based photosensitizer under photoredox catalysis conditions. Mechanistic studies reveal that the reaction might undergo radical addition of in situ-generated α-amino radical intermediates to alkynes followed by 1,5-hydrogen transfer, C-N bond cleavage, and concomitant isomerization of the resulting allyl radical species.

Donor-acceptor fluorophores as efficient energy transfer photocatalysts for [2 + 2] photodimerization.

Mild [2 + 2] photodimerization of enone substrates was induced by donor-acceptor fluorophores. Enone substrates were activated efficiently for anti-head to head dimerizations with a high yield (up to 83%) and high selectivity. The adjustable excited state potential also allows donor-acceptor fluorophores to be used for isomerization of the above substrates, confirming the potential of donor-acceptor fluorophores as energy transfer photocatalysts.

Reversible interconversion between methanol-diamine and diamide for hydrogen storage based on manganese catalyzed (de)hydrogenation.

The development of cost-effective, sustainable, and efficient catalysts for liquid organic hydrogen carrier systems is a significant goal. However, all the reported liquid organic hydrogen carrier systems relied on the use of precious metal catalysts. Herein, a liquid organic hydrogen carrier system based on non-noble metal catalysis was established.

Selective and Catalytic Hydrocarboxylation of Enamides and Imines with CO to Generate α,α-Disubstituted α-Amino Acids.

The first catalytic hydrocarboxylation of enamides and imines with CO to generate valuable α,α-disubstituted α-amino acids is reported. Notably, excellent chemo- and regio-selectivity are achieved, significantly different from previous reports on β-carboxylation of enamides, homocoupling or reduction of imines. Moreover, this transition-metal-free procedure exhibits low loading of an inexpensive catalyst, easily available substrates, mild reaction conditions, high efficiency, facile scalability and easy product derivatization, providing great potential for application in organic synthesis, pharmaceutical chemistry, and biochemistry.

Structure-Activated Copper Photosensitisers for Photocatalytic Water Reduction.

A series of phenanthroline-based ligands have been synthesised and their influence as bidentate nitrogen ligands in heteroleptic [Cu(P^P)(N^N)] photosensitisers in light-driven water reduction has been studied. In this noble-metal-free Cu-Fe-based photocatalytic water reduction system, the structural effects of the nitrogen ligands have been explored, including the steric and electronic effects of substituents at the 2,9- and 4,7-positions of phenanthroline. Ligands were prepared that led to increased hydrogen generation, with turnover numbers (TON ) of up to 1388 being observed.

Ligand-Controlled Cobalt-Catalyzed Transfer Hydrogenation of Alkynes: Stereodivergent Synthesis of Z- and E-Alkenes.

Herein, we report a novel cobalt-catalyzed stereodivergent transfer hydrogenation of alkynes to Z- and E-alkenes. Effective selectivity control is achieved based on a rational catalyst design. Moreover, this mild system allows for the transfer hydrogenation of alkynes bearing a wide range of functional groups in good yields using catalyst loadings as low as 0.

Copper-Based Photosensitisers in Water Reduction: A More Efficient In Situ Formed System and Improved Mechanistic Understanding.

The reduction of water has been achieved through a non-noble-metal-based homogeneous catalyst system that is formed in situ. Optimisation of the ligand quantities increased catalyst turnover numbers compared to preformed complexes. Mechanistic studies confirm a heteroleptic Cu complex as the active photosensitiser (PS) and an in situ formed Fe-phosphido dimer complex as the water reduction catalyst.

Insecticide Toxicity to Adelphocoris lineolatus (Hemiptera: Miridae) and its Nymphal Parasitoid Peristenus spretus (Hymenoptera: Braconidae).

In China, Adelphocoris lineolatus (Goeze) (Hemiptera: Miridae) is an important pest of alfalfa, cotton, and other crops, while Peristenus spretus (Chen & van Achterberg) (Hymenoptera: Braconidae) is the dominant nymphal parasitoid of this mirid bug. In the present study, the toxicity of 17 common insecticides to A. lineolatus was evaluated, and the susceptibility of P.

A noble-metal-free system for photocatalytic hydrogen production from water.

A series of heteroleptic copper(I) complexes with bidentate PP and NN chelate ligands was prepared and successfully applied as photosensitizers in the light-driven production of hydrogen, by using [Fe3(CO)12] as a water-reduction catalyst (WRC). These systems efficiently reduces protons from water/THF/triethylamine mixtures, in which the amine serves as a sacrificial electron donor (SR). Turnover numbers (for H) up to 1330 were obtained with these fully noble-metal-free systems.

Photocatalytic water reduction with copper-based photosensitizers: a noble-metal-free system.

Of noble descent: a fully noble-metal-free system for the photocatalytic reduction of water at room temperature has been developed. This system consists of Cu(I) complexes as photosensitizers and [Fe(3)(CO)(12)] as the water-reduction catalyst. The novel Cu-based photosensitizers are relatively inexpensive, readily available from commercial sources, and stable to ambient conditions, thus making them an attractive alternative to the widely used noble-metal based systems.

Effect of temperature on development, survival, and fecundity of Microplitis manilae (Hymenoptera: Braconidae).

Microplitis manilae Ashmead (Hymenoptera: Braconidae), a larval parasitoid, is a potential biological control agent of both Spodoptera exigua (Hübner) and Spodoptera litura (F.) (Lepidoptera: Noctuidae). Aspects of the climatic requirements for development, including survival, longevity, and fecundity of M.

The highly enantioselective Michael addition of ketones to nitrodienes catalyzed by the efficient organocatalyst system of pyrrolidinyl-thioimidazole and chiral thioureido acid.

The highly enantioselective Michael addition reaction of ketones to nitrodienes was promoted efficiently by the accessible and fine-tunable organocatalytic system of pyrrolidinyl-thioimidazole and chiral thioureido acid. The corresponding adducts were afforded in good yields with high diastereoselectivities (up to 99 : 1) and excellent enantioselectivities (up to 99% ee).

1-Nitro-4-(2-nitro-prop-1-en-yl)benzene.

The asymmetric unit of the title compound, C(9)H(8)N(2)O(4), contains two crystallographically independent mol-ecules, both of which adopt an E configuration about the C=C bond. In the crystal, the mol-ecules stack into columns along the c axis through π-π inter-actions, with centroid-centroid distances of 3.695 (3) and 3.

One-pot organocatalytic asymmetric synthesis of 3-nitro-1,2-dihydroquinolines by a dual-activation protocol.

Generally, amine-catalyzed enantioselective transformations rely on chiral enamine or unsaturated iminium intermediates. Herein, we report a protocol involving dual activation by an aromatic iminium and hydrogen-bonding. An enantioselective aza-Michael-Henry domino reaction of 2-aminobenzaldehydes with nitroolefins has been developed through this protocol using primary amine thiourea catalysts to provide a variety of 3-nitro-1,2-dihydroquinolines in moderate yields and with up to 90% ee.

Chiral amine/chiral acid as an excellent organocatalytic system for the enantioselective tandem oxa-Michael-aldol reaction.

The asymmetric tandem oxa-Michael-aldol reaction of salicylic aldehyde derivatives with alpha,beta-unsaturated aldehydes catalyzed by a chiral amine/chiral acid organocatalytic system was investigated. The organocatalytic system of (S)-diphenylpyrrolinol trimethylsilyl ether with chiral shift reagent (S)-Mosher acid presented a synergistic effect in the improvement of reaction performance and offered an efficient steric effect in the transformation. The tandem oxa-Michael-aldol reaction proceeded with high yields (up to 90%) and with excellent ee values (up to 99%) to give the corresponding chromene derivatives.

In situ enamine activation in aqueous salt solutions: highly efficient asymmetric organocatalytic Diels-Alder reaction of cyclohexenones with nitroolefins.

Deep-sea Diels-Alder: The asymmetric organocatalytic Diels-Alder reaction of cyclohexenones with aromatic nitroolefins can be carried out in seawater and brine. The reaction proceeds by an in situ enamine activation involving a one-step concerted addition pathway (see scheme).

[Comprehensive assessment on management measures of rice insect pests].

Based on the investigation of arthropods biodiversity and insect pests controlling effect in the paddy fields of demonstration area of organic rice production in Guangzhou, a comprehensive assessment on the economic, social, and ecological profits and costs of organic rice production in study area was conducted by using analytic hierarchy process (AHP). The results indicated that among all insect pests controlling measures, organic rice planting had the best comprehensive benefits, with a weight value of 0.5355.

(R)-7-Bromo-2,3,4,4a-tetra-hydro-1H-xanthen-1-one.

The title compound, C(13)H(11)BrO(2), contains a tricyclic ring system with one chiral center which exhibits an R configuration. The crystal structure is devoid of any classical hydrogen bonding.