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The direct cross-couplings of diaryl sulfoxides with aryl bromides via C-S bond cleavage could be readily accomplished using nickel(II) as the catalyst, 1,2-bis(diphenylphosphino)ethane (dppe) as the ligand, and magnesium turnings as the reducing metal in THF, leading to the corresponding biaryls in moderate to good yields. The reaction exhibited a broad substrate scope and could be applied to a gram-scale synthesis. The "one-pot" reaction, which avoids the utility of presynthesized and moisture-labile organometallic compounds, is operationally simple and step-economic.

Oncogenic stress induces DNA damage repair (DDR) that permits escape from mitotic catastrophe and allows early precursor lesions during the evolution of cancer. SAMHD1, a dNTPase protecting cells from viral infections, has been recently found to participate in DNA damage repair process. However, its role in tumorigenesis remains largely unknown. Here, we show that SAMHD1 is up-regulated in early-stage human carcinoma tissues and cell lines under oxidative stress or genotoxic insults. We further demonstrate that de-ubiquitinating enzyme USP7 interacts with SAMHD1 and de-ubiquitinates it at lysine 421, thus stabilizing SAMHD1 protein expression for further interaction with CtIP for DDR, which promotes tumor cell survival under genotoxic stress. Furthermore, SAMHD1 levels positively correlates with USP7 in various human carcinomas, and is associated with an unfavorable survival outcome in patients who underwent chemotherapy. Moreover, USP7 inhibitor sensitizes tumor cells to chemotherapeutic agents by decreasing SAMHD1 in vitro and in vivo. These findings suggest that de-ubiquitination of SAMHD1 by USP7 promotes DDR to overcome oncogenic stress and affect chemotherapy sensitivity.

Diverse 2,3-substituted indanones are accessed in an efficient and robust protocol by a rhodium-catalyzed tandem carborhodium/cyclization and intramolecular proton shift pathway. The reaction is compatible with a broad range of functional internal acetylenes, especially for natural and functionalized alkynes derivatives, affording the desired indanones in good to excellent yields. Remarkably, this reaction features very mild and sustainable conditions using water as the sole solvent and without exogenous ligands. Control studies support that indanone is formed through the intramolecular proton transfer process from the key intermediate indenol.

We report a general, scalable, and convenient photochemical process for diversities of distal oxygenated nitriles from corresponding less-strained ketoxime esters allowing one-step introductions of ether and cyano groups, which avoids the utilization of toxic cyanide reagents. A wide range of ketoxime esters involving five-membered to eight-membered cycloketoxime esters and linear ketoxime esters participate smoothly under operately simple and mild conditions, affording structurally variable ring-opening products.

A copper-catalysed three-component reaction utilizing readily available feedstocks was investigated, providing an operationally simple and practical route to trifluoromethyl allenes under mild and environmentally friendly conditions.

An efficient defluorinative net-[3 + 3]-cyclization strategy for the construction of perfluoroalkyl-substituted pyrimidine derivatives by using a series of perfluoroalkyl alkynes and amidines as starting materials was developed. The present reaction proceeded successfully under transition-metal-free conditions to form two new C–N bonds and a new heterocyclic ring through a sequence of hydroamination, defluorination, and annulation. The desired pyrimidines could be obtained with good functional group tolerance and moderate to good yields. Moreover, the distinctive fluorine effects of perfluoroalkyl substituents are vital for tuning the reactivity of alkynes for the anticipated defluorinative annulation. The pendant π system would lower associated bond dissociation energy significantly compared to that of a nonactivated C(sp3)–F bond.

The simple, commercially available ZnBr2 has been successfully employed as a highly efficient and chemoselective catalyst for the dehydrogenative borylation of terminal alkynes with HBpin under mild conditions. It shows a good tolerance toward various functional groups such as aryl, alkyl, heteroaryl, etc. The plausible reaction mechanism has been investigated based on the corresponding stoichiometric experiments and DFT calculations.

Progerin, a product of LMNA mutation, leads to multiple nuclear abnormalities in patients with Hutchinson-Gilford progeria syndrome (HGPS), a devastating premature aging disorder. Progerin also accumulates during physiological aging. Here, we demonstrate that impaired insulin-like growth factor 1 receptor (IGF-1R)/Akt signaling pathway results in severe growth retardation and premature aging in Zmpste24 −/− mice, a mouse model of progeria. Mechanistically, progerin mislocalizes outside of the nucleus, interacts with the IGF-1R, and down-regulates its expression, leading to inhibited mitochondrial respiration, retarded cell growth, and accelerated cellular senescence. Pharmacological treatment with the PTEN (phosphatase and tensin homolog deleted on chromosome 10) inhibitor bpV (HOpic) increases Akt activity and improves multiple abnormalities in Zmpste24-deficient mice. These findings provide previously unidentified insights into the role of progerin in regulating the IGF-1R/Akt signaling in HGPS and might be useful for treating LMNA -associated progeroid disorders.

We have developed a modular, convenient and practical copper-catalyzed platform for the preparation of alkene nitriles from corresponding cycloketoxime esters via radical-mediated C–C bond cleavage. A broad scope of cycloketoxime esters (4-membered to 8-membered) and some complex substrates derived from natural product derivatives performed well, affording corresponding ring opening products in the presence of copper salts. Moreover, the etherification, oxidation and alkynylation of cycloketoxime esters could also be achieved under variable copper-catalyzed conditions.

It is attractive to establish an efficient and practical platform affording functional compounds using readily available feedstocks as starting materials under mild conditions. We describe a direct copper-catalyzed fluorocarboalkynylation of the readily available alkynes with excellent regio- and stereoselectivity. A wide range of conjugated trifluoromethyl 1,3-enynes were obtained in good yields by this operationally simple strategy. The mechanistic experiments and DFT calculation revealed that a radical-mediated process was involved in the catalytic cycle.

Correction for ‘Copper-catalysed synthesis of trifluoromethyl allenes via fluoro-carboalkynylation of alkenes’ by Mengning Wang et al., Org. Chem. Front., 2022, 9, 1844–1849, https://doi.org/10.1039/D1QO01823J.

Septin4 is a tumor suppressor protein that promotes cell programmed death in various cell types through specifically antagonizing XIAP (X linked inhibitor of apoptosis), little is known its other novel binding partner and role in colorectal cancer. In this study, we found that Septin4 significantly expressed lower in human colon cancer when compared to peri-tumor benign cells, and its low expression was significantly associated with worse prognostic outcomes. Furthermore, Septin4 participated in DOX-induced colon cancer cell death in vitro. Septin4-overexpressing colon cancer cells displayed augmented apoptotic cell death and ROS production. Additionally, Septin4-knockdown cells revealed a resistance of DOX-induced cell death and reduced ROS production. Importantly, we first identified that BAX is a novel Septin4 binding partner and the interaction is enhanced under DOX treatment. Finally, Septin4-knockdown promoted colon cells growth in vivo. These observations suggest that Septin4 as an essential molecule contribute to the occurrence and development of human colon cancer and provide new technical approaches for targeted treatment of this disease.

Hydroboration, namely the direct addition of B-H bonds across C=O, C=N, C=C, C≡C and C≡N etc ., unsaturated bonds, is one of important methods for preparing organoborane compounds. Recently, the alkaline earth metal complexes have been widely employed as efficient catalysts for the hydroboration reaction. This article summarizes recent advancements in the alkaline earth metal (especially magnesium) catalyzed hydroboration of unsaturated organic compounds such as aldehydes, ketones, esters, amines, pyridines, nitriles, alkenes, alkynes, carbonates.

A series of asymmetrical β-diketiminate ligand stabilized magnesium(I) complexes have been successfully synthesized and structurally characterized via single crystal X-ray diffraction. When they were employed as efficient catalysts in the hydroboration of aryl, alkyl and alicyl epoxides with pinacolborane (HBpin), the resultant borate ester products were obtained with high yields and high regioselectivities. The results also revealed that they showed a marked preference for the branched Markovnikov hydroborated products instead of the linear anti-Markovnikov borate esters which are typically formed in protocols involving transition metal catalysts. The preliminary hydroboration reaction mechanism has been investigated via the corresponding DFT calculation.

The simple, commercially available ZnBr

A titanium(IV)-mediated ring-opening/dehydroxylative cross-coupling of diaryl-substituted methanols with a cyclopropanol derivative was developed. The reactions proceeded efficiently to provide synthetically useful γ,γ-diaryl esters in moderate to good yields, which could be applied to the functionalization of complex molecules derived from bioactive fenofibrate and isoxepac and the synthesis of a precursor of Zoloft.

Aging is a primary risk factor for neurodegenerative diseases, such as Alzheimer's disease (AD). SIRT2, an NAD

Proliferative vitreoretinopathy (PVR) is the most serious fibrous complication that causes vision loss after intraocular surgery, and there is currently no effective treatment in clinical. Autophagy is an important cell biological mechanism in maintaining the homeostasis of tissues and cells, resisting the process of EMT. However, it is still unclear whether autophagy could resist intraocular fibrosis and prevent PVR progression. In this study, we investigated the expression of mesenchymal biomarkers in autophagy deficiency cells and found these proteins were increased. The mesenchymal protein transcription factor Twist can bind to autophagy related protein p62 and promote the degradation of Twist, which reduced the expression of mesenchymal markers. By constructing an EMT model of retinal pigment epithelial (RPE) cells in vitro, we found that autophagy was activated in the EMT process of RPE cells. Moreover, in autophagy deficient RPE cell line via knockdown autophagy related protein 7 (Atg7), the expression of epithelial marker claudin-1 was suppressed and the mesenchymal markers were increased, accompanied by an increase in cell migration and contractility. Importantly, RPE epithelial properties can be maintained by promoting autophagy and effectively reversing TFG-β2-induced RPE fibrosis. These observations reveal that autophagy may be an effective way to treat PVR.

Tumor metastasis is a complex and multistep process and its exact molecular mechanisms remain unclear. We attempted to find novel microRNAs (miRNAs) contributing to the migration and invasion of breast cancer cells. In this study, we found that the expression of miR-487a was higher in MDA-MB-231breast cancer cells with high metastasis ability than MCF-7 breast cancer cells with low metastasis ability and the treatment with transforming growth factor β1 (TGF-β1) significantly increased the expression of miR-487a in MCF-7 and MDA-MB-231 breast cancer cells. Subsequently, we found that the transfection of miR-487a inhibitor significantly decreased the expression of vimentin, a mesenchymal marker, while increased the expression of E-cadherin, an epithelial marker, in both MCF-7 cells and MDA-MB-231 cells. Also, the inactivation of miR-487a inhibited the migration and invasion of breast cancer cells. Furthermore, our findings demonstrated that miR-487a directly targeted the MAGI2 involved in the stability of PTEN. The down-regulation of miR-487a increased the expression of p-PTEN and PTEN, and reduced the expression of p-AKT in both cell lines. In addition, the results showed that NF-kappaB (p65) significantly increased the miR-487a promoter activity and expression, and TGF-β1 induced the increased miR-487a promoter activity via p65 in MCF-7 cells and MDA-MB-231 cells. Moreover, we further confirmed the expression of miR-487a was positively correlated with the lymph nodes metastasis and negatively correlated with the expression of MAGI2 in human breast cancer tissues. Overall, our results suggested that miR-487a could promote the TGF-β1-induced EMT, the migration and invasion of breast cancer cells by directly targeting MAGI2.

A NCN-pincer ligand-based Mg-Li bimetallic complex [NCN-MgBr2][Li(THF)4] 1 has been employed as an efficient catalyst for cyanosilylation of a wide range of aldehydes with trimethylsilyl cyanide (TMSCN) at room temperature in CDCl3. In addition, catalyst 1 shows a good tolerance towards various functional groups such as amide, acid, ester, heterocyclic and alkene etc. The chemoselective cyanosilylation of aldehydes over ketones was also achieved under these conditions.

The well-defined lithium NCN-Pincer magnesiate complex [Li (THF)4][NCN-MgBr2] 2 based on a bis(imino)aryl ligand has been successfully prepared, crystallographic characterized and employed as an efficient catalyst for hydroboration of a wide range of aldehydes and ketones with pinacolborane (HBpin) at room temperature. Both aldehyde and ketone hydroboration proceeded efficiently (>99% conversion in

In this work, a novel fluorescent sensor (quercetin-Pluronic-F127 nano-micelles) was prepared by the facile self-assembly method with natural quercetin (Qc) and Pluronic-F127 (F127). Qc-F127 nano-micelles were characterized by TEM which indicated that Qc have successfully entered into the amphiphilic micelle. The nano micelles with sizes of 25 to 40 nm showed a strong green fluorescence (FL). The sensor exhibits high sensitivity and selectivity towards Cu2+ with a linear range of 5 × 10−8–4 × 10−6 mol L−1, the detection limit of 1 × 10−8 mol L −1. Moreover, the Qc-F127 nano-micelles can be used to detect Cu2+ in vitro due to their good biocompatibility. Besides Cu2+ sensing, when Cysteine (Cys) were added, the FL intensity of Qc-F127-Cu(II) system could be restored due to the chelation interactions between Cu2+ ions and the sulfydryl and amino groups of Cys. So, Qc-F127-Cu(II) system can used to detect Cys, and the linear range and the limit of detection of the Qc-F127-Cu2+ system were 3 × 10−7–3.5 × 10−5 mol L−1 and 6 × 10−8 mol L −1. Moreover, Qc-F127-Cu(II) has been used for imaging of Cys in cells, which demonstrates its values for potential application in biological systems.

A new honeycomb-like 2D Metal-organic polyhedral framework, {Cu3.75(BrCPEIP)2.5·(H2O)2.75·DMF}n (NJFU-5, H3BrCPEIP ​= ​5-((3-bromo-5-carboxyphenyl)ethynyl)isophthalic acid) was solvothermally synthesized and structurally characterized, which shows a BET surface area of 473 ​m2 ​g−1. Meanwhile, NJFU exhibits a comparably higher CO2 adsorption capacity of 37.0 ​cm3 ​g-1 (4.6 ​wt%) at 1 ​bar and 298 ​K in 2D MOF family, and a high CO2 selective adsorption toward N2 and CH4 as well.

A series of bulky secondary amines were treated with two equiv. Grignard reagent MeMgI at low temperature to yield the corresponding magnesium methyl complexes (1–4) in high yields. The prepared complexes have been comprehensively characterized. All four complexes exhibited very high reactivity as efficient pre-catalysts in the catalytic hydroboration of ketones with pinacolborane under mild conditions and at low catalyst loadings.

The organoplatinum complex containing ortho-metalated (S)-[1-(dimethylamino)ethyl]naphthalene as the chiral auxiliary has been used to promote the asymmetric cycloaddition reactions between 3,4-dimethyl-1-phenyl phosphole and (E)-1-phenyl-3-pyridin-2-yl-2-propenone or (E)-1-methyl-3-pyridin-2- yl-2-propenoate in high selectivity under mild condition. However, the corresponding palladium complex didn't show similar reactivity. This Diels−Alder reaction generated five new stereogenic centers in a single step. The naphthylamine auxiliary could be removed chemoselectively from the template products by treatment with concentrated hydrochloric acid to form the corresponding dichloro platinum complexes [(P−N)PtCl2]. The molecular structure and absolute configuration of the major dichloro platinum complex have been resolved by single-crystal X-ray diffraction. Finally, the enantiomerically pure P−N ligands can be readily liberated from the corresponding dichloro platinum complexes as air-sensitive solids by treatment with aqueous potassium cyanide in quantitative yield.

A simple catalyst-free and solvent-free method for the cyanosilylation of a variety of aldehydes with trimethylsilyl cyanide as well as the Knoevenagel condensation reaction of various aldehydes with malononitrile was developed. The developed protocol demonstrated high efficiency in the two C–C bond formation scenarios.

The organopalladium complex containing ortho-metalated (S)-[1-(dimethylamino)ethyl]naphthalene as the chiral auxiliary has been successfully employed to promote the asymmetric Diels–Alder reaction between 3,4-dimethyl-1-phenylphosphole and (Z)-diphenyl-1-styrylphosphine or (E)-diphenyl-1-styrylphosphine. In the intramolecular cycloaddition reaction between (E)-diphenyl-1-styrylphosphine and 3,4-dimethyl-1-phenylphosphole, a pair of diastereomeric endo-cycloadducts were obtained in the ratio of 1:1. However, the asymmetric reaction between (Z)-diphenyl-1-styrylphosphine and 3,4-dimethyl-1-phenylphosphole also produced the same endo-product in the same stereoselectivity unexpectedly. The chiral naphthylamine auxiliary could be removed chemoselectively from the template by treatment with concentrated hydrochloric acid to generate the neutral stable dichloro complex [(P–P)PdCl2]. Treatment of the dichloro complex with KCN gave the pure bis-phosphine ligand in quantitative yield.

The organopalladium complex containing ortho-metalated (R)-[1-(dimethylamino) ethyl]naphthalene as the chiral auxiliary has been used as the chiral template to promote the asymmetric hydrophosphination reaction between diphenylphosphine and 2-ethynylpyridine in high selectivity under mild conditions. The double hydrophosphination reaction produces four stereoisomeric products in the ratio of 1:19.4:2.4:1.3. The naphthylamine auxiliary could be removed chemoselectively from the template products by treatment with concentrated hydrochloric acid to form the corresponding chiral dichloro complexes [(P–P)PdCl2]. The molecular structure and absolute configuration of the dichloro complex have been resolved by single-crystal X-ray crystallography. It confirms that the asymmetric diphosphines as P–P bidentate chelate on the chiral naphthylamine palladium templates. Finally, the enantiomerically pure diphosphine ligand with chirality on the carbon backbone can be readily liberated from the dichloro palladium complex as an air-sensitive solid by treatment of the complex with aqueous potassium cyanide in high yield.

Wnt/β-catenin signaling pathway influences embryonic development, cell polarity and adhesion, apoptosis and tumorigenesis. MicroRNAs (miRNAs) function as important regulators of the tumorigenesis and metastasis. In the present study, we aimed to find novel targets and mechanisms of microRNA-148a (miR-148a) in regulating the migration and invasion of breast cancer cells. In the present study, miR-148a was found downregulated in human breast cancer tissues and cell lines. The ectopic miR-148a expression inhibited the migration and invasion of MCF-7 and MDA-MB-231 breast cancer cells. Furthermore, we demonstrated that WNT-1, one of the ligands of Wnt/β-catenin signaling pathway, was a direct target of miR-148a. The overexpression of miR-148a reduced the mRNA and protein expression levels of WNT-1, also decreased the expression levels of the key components of Wnt/β-catenin pathway, including β-catenin, metalloproteinase-7 (MMP-7) and T-cell factor-4 (TCF-4) in MCF-7 and MDA-MB-231 cells. In addition, the data showed that the expression of WNT-1 was significantly higher in human breast cancer tissues compared with the adjacent normal tissues and the expression of miR-148a was negatively correlated with the WNT-1 expression in human breast cancer tissues. Taken together, our results suggest that miR-148a can suppress the migration and invasion of breast cancer cells by targeting WNT-1 and inhibiting Wnt/β-catenin signaling pathway and this will provide new insights into the molecular mechanisms of breast cancer metastasis.

Wnt/β-catenin signaling pathway plays a major role in the cancer metastasis. Several microRNAs (miRNAs) are contributed to the inhibition of breast cancer metastasis. Here, we attempted to find novel targets and mechanisms of microRNA-100 (miR-100) in regulating the migration and invasion of breast cancer cells. In this study, we found that miR-100 expression was downregulated in human breast cancer tissues and cell lines. The overexpression of miR-100 inhibited the migration and invasion of MDA-MB-231 breast cancer cells. Inversely, the downregulation of miR-100 increased the migration and invasion of MCF-7 breast cancer cells. Furthermore, FZD-8, a receptor of Wnt/β-catenin signaling pathway, was demonstrated a direct target of miR-100. The overexpression of miR-100 decreased the expression levels not only FZD-8 but also the key components of Wnt/β-catenin pathway, including β-catenin, metalloproteniase-7 (MMP-7), T-cell factor-4 (TCF-4), and lymphoid enhancing factor-1 (LEF-1), and increased the protein expression levels of GSK-3β and p-GSK-3β in MDA-MB-231 cells, and the transfection of miR-100 inhibitor in MCF-7 cells showed the opposite effects. In addition, the expression of miR-100 was negatively correlated with the FZD-8 expression in human breast cancer tissues. Overall, these findings suggest that miR-100 suppresses the migration and invasion of breast cancer cells by targeting FZD-8 and inhibiting Wnt/β-catenin signaling pathway and manipulation of miR-100 may provide a promoting therapeutic strategy for cancer breast treatment.

The first example of an enantioselective hydrophosphination reaction of ethenesulfonyl fluoride derivatives catalyzed by a phosphapalladacycle afforded chiral sulfonyl fluoride-derived phosphines in quantitative yields and enantioselectivities of up to 93% ee. Investigations revealed the importance of adjacent vacant sites within the active metal center for intramolecular nucleophilic attack to provide the functionalized phosphine.

The well-defined heavy rare-earth ytterbium iodide complex 1 (L2YbI) has been successfully employed as an efficient catalyst for the hydroboration of a wide range of aldehydes and ketones with pinacolborane (HBpin) at room temperature. The protocol requires low catalyst loadings (0.1-0.5 mol %) and proceeds rapidly (>99% conversion in

Lanthanide complexes supported by the tetradentate amine-bridged bis(phenolate) ligand LH2 [L = Me2NCH2CH2N{CH2-(2-O–C6H2– Bu 2 t -3,5)}2] were synthesized and structurally characterized. The reaction of (tBuCp)2NdCl(THF)2 with ligand LH2 in a 1:1 M ratio in THF at room temperature gave the amine-bridged bis(phenolate) lanthanide chloride LNdCl(DME) 1, (DME = 1,2-dimethoxyethane) in high yield. Complex 1 reacted with potassium amide to give the corresponding neodymium amido product LNdNPh2(DME) (2) in good yield. The ligand LH2 was subsequently treated with Cp3Ln to produce the amine-bridged bis(phenolato) cyclopentadienyl lanthanide complexes LLnCp(THF) (Ln = Yb (3) and Nd(4)). The definitive solid state molecular structure of complexes 1 and 3 were confirmed by single-crystal X-ray analysis. In complex 1 the central Nd atom is seven-coordinated with the coordination sphere completed by two oxygen atoms and two nitrogen atoms of the amine-bridged bis(phenolate) ligand, two oxygen atoms of DME molecule and one chlorine atom in a distorted capped octahedron while in complex 3 the Yb atom is six-coordinated by two oxygen atoms and two nitrogen atoms from the ligand, one oxygen atom from the coordinated THF molecule and a cyclopentadienyl group in a distorted octahedron.

A porous cobalt-based metal–organic framework [CoL2−]n (L = 5-(pyrimidin-5-yl) isophthalic acid) (termed NJFU-2), has been designed by self-assembling [Co2(COO)4] paddlewheel SBUs and a novel trigonal hetero-functional ligand. Moreover, the activated sample NJFU-2a exhibits a moderate BET surface area of 1223 m2 g−1, large CO2 uptake (6.14 wt% at 0.15 bar and 298 K) and high selectivity for CO2 over CH4 and N2 at room temperature, estimated by the Ideal Adsorbed Solution Theory (IAST).

Asymmetric cycloaddition reaction between 3,4-dimethyl-1-phenylarsole and ethyl vinyl ketone was promoted by the palladium complex containing ortho-metalated (S)-[1-(dimethylamino)ethyl]naphthalene as the chiral auxiliary. The keto group in the resulting arsanorbornene cycloadducts could be located stereospecifically in the endo or exo position by controlling the electronic properties of the organopalladium promoter. In the intermolecular cycloaddition reaction, a pair of separable diastereomeric palladium complexes was obtained in the ratio of 2:1. In the intramolecular process, however, only one As–O bidentate arsanorbornene palladium complex was produced stereoselectively. The arsenic-elimination reaction was readily observed on the corresponding endo- and exo-ketoarsine ligands. The absolute configuration and the coordination property of the enantiomerically pure endo-cycloadduct had been established by single-crystal X-ray analysis.

The organopalladium complex containing ortho-metalated (S)-[1-(dimethylamino)ethyl]naphthalene as the chiral template was employed to promote the asymmetric cycloaddition reaction between 3,4-dimethyl-1-phenylarsole and diphenylvinylphosphine. It has been proven that the chiral template incorporating napthylamine is more efficient than the benzylamine based analogue as evidenced by the drastic improvement in stereoselectivity and reaction rate. However, when no chiral template was employed, trans-[PdI2(3,4-dimethyl-1-phenylarsole)2] reacted with trans-[PdI2(diphenylvinylphosphine)2] producing a structurally novel diiodo complex, as a result of an interesting selective cleavage of one As–C bond in the norbornene skeleton and subsequent rearrangements within the skeletal framework. The molecular structure of the diiodo product has been confirmed by X-ray crystallography. Structural analysis showed that in addition to the normal As–P five-membered ring, there is one new five-membered ring containing As–O bond being formed during the course of the reaction along with another seven-membered ring incorporating a hydroxy group.

The organopalladium complex containing ortho-metalated ( S )-[1-(dimethylamino)ethyl]naphthalene as the chiral auxiliary has been used as the chiral template to promote the asymmetric cycloaddition reaction between phenyldivinylphosphine and 3,4-dimethyl-1-phenylarsole. The reaction was completed in 1 h at room temperature, with the formation of two isomeric cycloadducts in the ratio 1:3. The major phenylvinylphosphino-substituted asymmetrical hetero-bidentate arsanorbornene ligand with chirality residing on both As and P centers was obtained stereoselectively on the chiral palladium template in moderate yield. The chiral heterobidentate ligand was isolated in its enantiomerically pure form by removal of the chiral auxiliary using concentrated hydrochloric acid and subsequent cleavage from the neutral complex [(As–P)PdCl 2 ] by using potassium cyanide. Similar to the earlier reported analogous diphenylphosphino-substituted asymmetrical heterobidentate arsanorbornene (As–P) ligand, an arsenic elimination process was also found in the dichloro and dibromo palladium complex whereas the diiodo species did not show similar reactivity, but the corresponding η 2 diiodo complex could be obtained from the η 2 dibromo complex by treatment with sodium iodide.

The asymmetric [4+2] Diels-Alder reaction involving 3,4-dimethyl-1-phenylphosphole, DMPP, as the cyclic diene and its P-sulfonated analogue DMPP S as the dienophile was carried out by utilizing the palladium(II) template complex containing ortho-metalated (R)-(1-(dimethylamino)ethyl)naphthalene as the chiral auxiliary. The reaction proceeded regiospecifically and stereoselectively to give corresponding phosphanorbornene ligand as the major product. Throughout the cycloaddition reaction, DMPP functions chemoselectively as the cyclic diene whilst DMPP S assumes the role of dienophile. The absolute stereochemistry of the novel chiral heteroditopic ligand was established by means of single crystal X-ray diffraction analysis.

A series of enantiomerically pure 1,2-diester substituted P,N-ligands incorporating two chiral carbons in the backbone were generated in high yields and high stereoselectivity from acetylenedicarboxylate via initial hydrophosphination using diphenylphosphine followed by hydroamination with various primary and secondary amines. The reactions were activated and stereochemically controlled by the organopalladium complex containing ortho-palladated (S)-(1-(dimethylamino)ethyl)naphthalene under mild conditions. The absolute stereochemistry and the coordination chemistry of P,N-products were determined by the single crystal X-ray diffraction analysis. All the chiral P,N-ligands could be liberated from the palladium template without loss of optical purity. Subsequent recomplexation to selected chiral palladium centers confirmed the optical purity of the new functionalized chiral P,N-ligands.