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Using a coordinatively unsaturated 16-electron mononuclear ruthenium(II)-pyrazolyl-imidazolyl-pyridine complex [Ru(II)–NNN] as the building block and oligopyridines as the polydentate ligands, pincer-type tri- and hexanuclear ruthenium(II) complexes [Ru(II)–NNNN]nwere efficiently assembled. These complexes were characterized by elemental analyses, NMR, IR, and MALDI-TOF mass spectroscopies. In refluxing 2-propanol, the multinuclear ruthenium(II)–NNNN complexes exhibited exceptionally high catalytic activity for the transfer hydrogenation of ketones at very low concentrations and reached turnover frequencies (TOFs) up to 7.1 × 106h–1, featuring a remarkable cooperative effect from the multiple Ru(II)–NNNN functionalities. DFT calculations have revealed the origin of the high catalytic activities of these Ru(II)–NNNN complexes.

The Sunda Shelf plays a key role in the sedimentation of the southern South China Sea (SCS). However, the impact of past climate changes on sediment transfer to the Sunda Shelf and the southern SCS is still unresolved. Here, we present new data on grain size, clay mineralogy, and Sr‐Nd isotopes of three marine cores, river sediments, and surface sediments of the Sunda Shelf. The results indicate that clay fractions of the central Sunda Shelf and the Gulf of Thailand derived mainly from the Mekong River and the rivers of northern Thailand since the last deglaciation. Significant changes in sediment sources are observed at 7.5 cal ka BP. From 13.3 to 7.5 cal ka BP, sediments in the Gulf of Thailand mainly originated from the rivers of northern Thailand, with contributions from the Mekong River increasing after 7.5 cal ka BP. An opposite shift is observed in the central Sunda Shelf. Such variations in the spatial distribution result from a combination of sea level and East Asian monsoon effects. After 7.5 cal ka BP, less Mekong River sediments were transported southeastwards into the southern SCS, and more sediments were gradually trapped within the delta and transported in a southwesterly direction into the Gulf of Thailand due to intense East Asian winter monsoon, which forced a strong southwestward coastal current. Our results demonstrate the important impact of East Asian winter monsoon strengthening and sea level rise in the mid‐Holocene, which can change sediment sources and transport processes on the Sunda Shelf. Sea level and monsoon are two important factors controlling sediment transfer in the tropical and subtropical continental marginal seas. However, the impact of past sea level and monsoon changes on mineralogical composition and sediment transfer to the Sunda Shelf (the largest low‐latitude continental shelf) and the southern South China Sea (SCS) is unclear. This study provides new data on grain size, clay mineralogy, and Sr‐Nd isotopes of sediment from marine cores, river sediments, and surface sediments of the Sunda Shelf to constrain sediment sources and climatic control on sediments deposited on the Sunda Shelf since the last deglaciation. We find that the Mekong River and the rivers of northern Thailand are two major sediment sources to the Sunda Shelf. An opposite shift of sediment sources at 7.5 cal ka BP is observed between the Gulf of Thailand and the central Sunda Shelf, which results from the transfer of the Mekong River sediments between the southern SCS and the Sunda Shelf caused by sea‐level rise and East Asian winter monsoon strengthening in the mid‐Holocene. Our results highlight that sea level and East Asian winter monsoons can significantly change sediment sources and transport processes on the Asian low‐latitude continental shelf. Clay minerals and Sr‐Nd isotopes identified sediment sources to the Sunda Shelf since the last deglaciation as Mekong and Thailand riversEstimation of the Mekong and Thailand river inputs to the sedimentation of the Sunda Shelf and the southern South China SeaSea‐level rise and East Asian winter monsoon strengthening drove major sediment‐source changes on the Sunda Shelf at 7.5 ka BP Clay minerals and Sr‐Nd isotopes identified sediment sources to the Sunda Shelf since the last deglaciation as Mekong and Thailand rivers Estimation of the Mekong and Thailand river inputs to the sedimentation of the Sunda Shelf and the southern South China Sea Sea‐level rise and East Asian winter monsoon strengthening drove major sediment‐source changes on the Sunda Shelf at 7.5 ka BP

Carbon–carbon bond formation is among the most important reactions in organic synthesis. Reconstruction of a carbon–carbon bond through ring-opening C–C bond cleavage of a strained carbocycle usually occurs via a thermodynamically preferable pathway. However, carbon–carbon bond formation through thermodynamically less favorable C–C bond cleavage has seldom been documented. Herein, we disclose an unusual C–C bond cleavage of cycloketone oxime esters for [4+1] annulation. Under anaerobic copper(I) catalysis, cycloketone oxime esters underwent regioselective, thermodynamically less favorable radical C–C bond cleavage followed by annulation with enaminothiones; that is, α-thioxo ketene N,S-acetals efficiently affording 2-cyanoalkyl-aminothiophene derivatives. Cyclobutanone, -pentanone, -hexanone, and -heptanone oxime esters could act as the effective C1 building blocks in the annulation reaction. An iminyl radical mechanism is proposed for the rare C–C bond cleavage/[4+1] annulation cascade.

The direct synthesis of triazole 2-oxides has posed a challenge in the field of N-heterocyclic chemistry. A novel copper(I)-catalyzed nitrosylation/annulation cascade of enaminones provides a straightforward route to 1H-1,2,3-triazole 2-oxides by forming new C–N, N=N, and N–N bonds using noncorrosive tert-butyl nitrite (TBN) as both the N and NO sources. The synthetic protocol features easily accessible starting materials, wide substrate scopes, and good tolerance toward various functional groups while avoiding use of explosive azides.

Salient regions detection and segmentation of an image is very important for many applications like content-based image retrieval (CBIR), object recognition, and content delivery. But in the practical environment, there may be many or heavy level of noisy in the input image. For a better effect, a new method is proposed in this paper: denoise the input image by using a good performance algorithm, and then detect and segment the salient regions which we are concerned with. We compare our new method with the current method, the experimental results demonstrate that our method performs well and reaches a good result of image saliency regions detection and segmentation.

Versatile syntheses of secondary and tertiary amines by highly efficient direct N‐alkylation of primary and secondary amines with alcohols or by deaminative self‐coupling of primary amines have been successfully realized by means of a heterogeneous bimetallic Pt–Sn/γ‐Al2O3catalyst (0.5 wt % Pt, Pt/Sn molar ratio=1:3) through a borrowing‐hydrogen strategy. In the presence of oxygen, imines were also efficiently prepared from the tandem reactions of amines with alcohols or between two primary amines. The proposed mechanism reveals that an alcohol or amine substrate is initially dehydrogenated to an aldehyde/ketone or NH‐imine with concomitant formation of a [PtSn] hydride. Condensation of the aldehyde/ketone species or deamination of the NH‐imine intermediate with another molecule of amine forms an N‐substituted imine which is then reduced to a new amine product by the in‐situ generated [PtSn] hydride under a nitrogen atmosphere or remains unchanged as the final product under an oxygen atmosphere. The Pt–Sn/γ‐Al2O3catalyst can be easily recycled without Pt metal leaching and has exhibited very high catalytic activity toward a wide range of amine and alcohol substrates, which suggests potential for application in the direct production of secondary and tertiary amines and N‐substituted imines.

Exceptionally active ruthenium(II) complexeswithout an ancillary NH functionality, but bearing a (chiral) unsymmetrical pyridyl‐benzimidazolyl‐based NNN ligand, exhibited very high catalytic activity in the (asymmetric) transfer hydrogenation ((A)TH) of ketones. The corresponding RuH complex, which is presumably the catalytically active species, was successfully isolated and structurally characterized by X‐ray crystallography.

The catalyst allows a direct bis‐amination of diols with primary and secondary amines.

An efficient Pt—Sn/γ‐Al2O3‐catalyzed synthesis of secondary and tertiary amines by direct N‐alkylation of primary and secondary amines, respectively, with alcohols or by deaminative self‐coupling of amines is developed.

Newly synthesized ruthenium(II) complexes bearing an unsymmetrical pyridyl‐benzimidazolyl‐based ligand exhibit high catalytic activity for transfer hydrogenations of aromatic and cyclic ketones.