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The reactivity of diazadiphosphapentalene 1 towards various substrates was investigated. Reaction of 1 with ammonia-borane resulted in transfer hydrogenolysis concomitantly with the cleavage of a P-N bond. By treatment of 1 with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), oxidation took place at one of the phosphorus atoms of 1, and a PV/PIII mixed-valence derivative was isolated. At the same time, it was demonstrated that only one of the phosphorus atoms in 1 behaves as an electron donor for electrophiles and Lewis acids. The former afforded an intramolecularly coordinated phosphine-phosphenium species, whereas the latter demonstrates the ligand property of 1. UV irradiation induced rearrangement of 1 into another example of another diazadiphosphapentalene. [ABSTRACT FROM AUTHOR]

The syntheses and structures of heteroleptic germanium(II) and tin(II) chlorides supported by anionic ligands derived from 2,3-dimethyl-1,4-diaza-1,3-butadiene are described. The reaction of ArN=C(Me)C(Me)=NAr ( L, Ar = 2,6- iPr2C6H3) with MeLi in Et2O, followed by treatment with GeCl2 ·dioxane or SnCl2, afforded [ L1ECl] [ L1 = ArN=C(Me)C(Me)2NAr; E = Ge ( 1), Sn ( 2)]. Moreover, L2Li [ L2 = ArN=C(Me)C(=CH2)NAr] reacted with GeCl2 ·dioxane in Et2O to form [{C(=CH)NAr}{C(Me)=NAr}]2(GeCl)2 ( 3). The byproducts are [{C(CH2)NAr}{C(Me)=NAr}Ge]2 ( 4) and L2H ( 5). Furthermore, the reaction of L with LiN iPr2 in Et2O, followed by treatment with SnCl2, afforded [ L2SnCl] ( 6). Compounds 1- 4 and 6 have been characterized by NMR spectroscopy and X-ray crystallography. [ABSTRACT FROM AUTHOR]

The reaction of the tin(II) (iminophosphinoyl)(thiophosphinoyl)methanediide[(PPh2NSiMe3)(PPh2S)CSn:]2(1) with AdNCO (Ad = adamantyl), ArNCO (Ar =2,6-Pri2C6H3), and [RhCl(cod)]2in THF afforded [(PPh2NSiMe3)(PPh2S)C{C(O)N(Ad)}Sn:] (2), [(PPh2NSiMe3)(PPh2S)C¯{C(O)N(Ar)}Sn:] (3), and[(PPh2NSiMe3)(PPh2S)C{Rh(cod)}(SnCl)](4), respectively. Compounds 2–4have been characterized by NMR spectroscopy and X-ray crystallography. [ABSTRACT FROM AUTHOR]

Abstract: The reaction of [Cp∗IrCl2]2 (Cp*= η 5 −C5Me5) with the tridentate 3-thiapentane-1,5-dithiolate ligand, S(CH2CH2S−)2 (tpdt), led to the formation of [Cp∗Ir(η 3 −tpdt)] (1) in 81% isolated yield. Subsequent reactions of 1 with [Cp∗IrCl2]2 in 2:1 and 1:1 molar equiv ratios resulted in the formation of [Cp∗Ir(μ − η 2:η 3 −tpdt)Cp∗IrCl][PF6] (2) and [Cp∗Irμ − η 2:η 3 −tpdt)Cp∗IrCl][Cp∗IrCl3] (3) in 86 and 79% yields, respectively, based on 1, whereas the reactions of 1 with [(COD)IrCl]2 (COD=1,5-cyclooctadiene) in 2:1 and 1:1 molar equiv ratios resulted in the formation of the homo-bimetallic derivatives Cp∗Ir(μ − η 1:η 3 −tpdt)(COD)IrCl (4) (92% yield) and [Cp∗Ir(μ − η 2:η 3 −tpdt)(COD)Ir] [(COD)IrCl2] (5) (82% yield). Reactions between 1 and [(COD)RhCl]2, yielded the hetero-bimetallic derivatives Cp∗Ir(μ − η 1:η 3 −tpdt)(COD)RhCl (6) and [Cp∗Ir(μ − η 2:η 3 −tpdt)(COD)Rh][(COD)RhCl2] (7), in 92 and 93% yields, respectively. The reaction of 1 with methyl iodide gave mono-methylated derivative [Cp∗Ir(η3-C4H8S3Me)]I (8) (93% yield). All these compounds have been comprehensively characterized. [Copyright &y& Elsevier]

Abstract: Chemical examination of a Chinese soft coral Sinularia rigida resulted in the isolation and characterization of 19 new cembrane-type diterpenoids, designated as sinulariols A–S (1–19). Their structures were determined on the basis of extensive spectroscopic (2D NMR, IR, and MS) analysis in association with modified Mosher’s method. All compounds featured unusual 19-oxygenated functionalities, which are rarely found from cembranoid family. The biogenetic transformation of the isolated compounds is postulated. Part of the isolated cembranoids showed significant anti-fouling activity. [Copyright &y& Elsevier]

Secondary phosphirane complexes isomerize above 100 °C to give the corresponding terminal phosphinidene complexes, which can be trapped by alkenes and alkynes. This reaction is a rare instance of the isomerization of a PIII derivative into a PI derivative. It appears to mimic the reductive elimination of alkanes from transition-alkylmetal hydrides. [ABSTRACT FROM AUTHOR]

Abstract: A novel covalently modified glassy carbon electrode (GCE) with poly (vinyl alcohol) (PVA) has been fabricated through an electrochemical oxidation procedure and was used to electrochemically detect dopamine (DA), ascorbic acid (AA), uric acid (UA) and their mixture by a differential pulse voltammetry (DPV) method. The modified GCE exhibits potent and persistent electron-mediating behavior followed by well-separated oxidation peaks in cyclic voltammetry (CV) or DPV towards DA, AA and UA with activation overpotentials. For the ternary mixture containing DA, AA and UA, the three compounds can well be separated from each other at a scan rate of 0.50Vs−1 with a potential difference of 140mV, 140mV and 280mV in CV, and 180mV, 130mV and 310mV in DPV between DA and AA, DA and UA, and UA and AA, respectively. The differences are large enough to determine AA, DA and UA individually and simultaneously. The stability of the PVA covalently modified GCE is good up to at least 30 days of continual operation. [Copyright &y& Elsevier]

Thereaction of transient [MeP-W(CO)5] with norbornene givesthe two corresponding exophosphiranes with W synor antito the norbornane bridge. The syncomplex is selectively decomplexed by carbon monoxideat 120 °C under 50 bar. Both complexes are easily cleaved byPd(OAc)2at room temperature to give [MeP(OAc)2)]W(CO)5. [ABSTRACT FROM AUTHOR]

The reaction of the NHC-disilicon(0) complex [(IAr)Si=Si(IAr)] ( 1, IAr=:C{N(Ar)C(H)}2, Ar=2,6- iPr2C6H3) with two equiv of elemental Te in toluene at room temperature for three days afforded a mixture of the first dimeric NHC-silicon monotelluride [(IAr)Si=Te]2 ( 2) and its isomeric complex [(IAr)Si(μ-Te)Si(IAr)=Te] ( 3). When the same reaction was performed for ten days, only 3 was isolated from the reaction mixture. Compound 1 reacted with four equiv of elemental Te in toluene for four weeks, which proceeded through the formation of 2, 3 and the NHC-disilicon tritelluride complex [{(IAr)Si(=Te)}2Te] ( 5-Te), to form the dimeric NHC-silicon ditelluride [(IAr)Si(=Te)(μ-Te)]2 ( 4). The reactions are in line with theoretical mechanistic studies for the formation of 4. Compound 3 reacted with one equiv of elemental sulfur in toluene to form the first NHC-disilicon sulfur ditelluride complex [{(IAr)Si(=Te)}2S] ( 5-S). [ABSTRACT FROM AUTHOR]

Molecular evolution, with self-organization of simple molecules towards complex functional systems, provides a new strategy for biomimetic architectonics and perspectives for understanding the complex processes of life. However, there remain many challenges to fabrication of systems comprising different types of units, which interact with one another to perform desired functions. Challenges arise from a lack of stability, dynamic properties, and functionalities that reconcile with a given environment. A co-assembling fiber system composed of simple peptide and porphyrin is presented. This material is considered a prebiotic assembly of molecules that can be rather stable and flexibly self-functionalized with the assistance of visible light in a 'prebiotic soup'; acidic (pH 2), hot (70 °C), and mineral-containing (Na+, Ti4+, Pt2+, and so forth) water. The co-assembled peptide-porphyrin fiber, with self-mineralized reaction centers, may serve as a primitive photobacteria-like cellular model to achieve light harvesting, energy transfer, and ultimately sustainable hydrogen evolution. [ABSTRACT FROM AUTHOR]

The synthesis and characterization of the stannylidenideanion[LSn:]−(L = 2,6-(CHNBut)2C6H3) supported by the 2,6-diiminophenylligand is described. The reaction of the chlorostannylene [LSnCl](2) with excess KC8in diethyl ether at roomtemperature afforded the distannylene [LSn:]2(3). The treatment of 3with 2 equiv of KC8in tetrahydrofuran (THF) resulted in the cleavage of the SnI–SnIbond in 3to afford thepotassium stannylidenide [LSnK·THF] (4). The molecularstructure of compound 4as determined by single-crystalX-ray diffraction analysis shows that the K atom is η5-coordinated to the low-valent tin heterocycle. Moreover, the negativecharge at the Sn atom in compound 4is stabilized byan electron delocalization in the low-valent tin heterocycle. [ABSTRACT FROM AUTHOR]

Abstract: The asymmetric hydroarsination reactions between diphenylarsine and 3-diphenylphosphanyl-but-3-en-1-ol and 2-diphenylphosphanyl-prop-2-en-1-ol have been achieved using the organopalladium complex containing ortho-metallated (R)-[1-(dimethylamino)ethylnaphthalene as the chiral reaction template in high stereoselectivities under mild conditions. Hydroarsination of 3-diphenylphosphanyl-but-3-en-1-ol with diphenylarsine generated only one stereoisomer as five-membered As–P bidentate chelate on chiral naphthylamine palladium template. Using the same chiral metal template, similar hydroarsination reaction was carried out on 2-diphenylphosphanyl-prop-2-en-1-ol which gave two different products in the ratio of 2.6 to 1. The major isomer was identified as the expected five-membered As–P bidentate ligand and the minor isomer was identified as the elimination product. The naphthylamine auxiliary could be removed chemoselectively by treatment with concentrated hydrochloric acid. Optically pure As–P ligands containing the hydroxy groups at the chiral carbon centres were prepared by ligand displacement. The absolute configuration and coordination properties of the complexes have been established by single crystal X-ray analysis. [Copyright &y& Elsevier]

Abstract: Cyano-functionalized allylic phosphine substrates containing the ortho-metalated (R)-(1-(dimethylamino)ethyl)naphthalene as the chiral auxiliary were synthesized from bromoacetaldehyde dimethylacetal via a one-pot process. The diastereoselective hydrophosphination reactions of the cis- and trans-allylic phosphine substrates gave the cyano-functionalized chiral 1,2-bis(diphenylphosphino)ethane products with high yield and stereoselectivity. The subsequent organic transformation reactions of the cyano-substituted products chemoselectively afforded the formyl- and hydroxyl-functionalized chiral 1,2-diphosphine complexes with retention of stereochemistry. The coordination properties and absolute configurations of the novel 1,2-diphosphine complexes were established by single crystal X-ray crystallography. The optically pure 1,2-bis(diphenylphosphino)ethane ligands with cyano-, formyl- and hydroxyl-functionalities could be liberated in high yields from the corresponding dihalo palladium complexes by treatment with aqueous potassium cyanide. [Copyright &y& Elsevier]

The trapping of a silicon(I) radical with N-heterocyclic carbenes is described. The reaction of the cyclic (alkyl)(amino) carbene [cAACMe] (cAACMe=:C(CMe2)2(CH2)NAr, Ar=2,6- iPr2C6H3) with H2SiI2 in a 3:1 molar ratio in DME afforded a mixture of the separated ion pair [(cAACMe)2Si:.]+I− ( 1), which features a cationic cAAC-silicon(I) radical, and [cAACMe−H]+I−. In addition, the reaction of the NHC-iodosilicon(I) dimer [IAr(I)Si:]2 (IAr=:C{N(Ar)CH}2) with 4 equiv of IMe (:C{N(Me)CMe}2), which proceeded through the formation of a silicon(I) radical intermediate, afforded [(IMe)2SiH]+I− ( 2) comprising the first NHC-parent-silyliumylidene cation. Its further reaction with fluorobenzene afforded the CAr−H bond activation product [1-F-2-IMe-C6H4]+I− ( 3). The isolation of 2 and 3 confirmed the reaction mechanism for the formation of 1. Compounds 1- 3 were analyzed by EPR and NMR spectroscopy, DFT calculations, and X-ray crystallography. [ABSTRACT FROM AUTHOR]

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)PdCl 2 ]. 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. [ABSTRACT FROM AUTHOR]

The article presents the steps of the chemical equations involved in the addition of diphenylphosphine to 3-methyl-4-nitro-5-alkenylisoxazoles.

The reaction of H2with [RP-W(CO)5] (R =Ph, Me) above 120 °C leads, first, to the secondary diphosphinecomplex (RPH-PHR)(W(CO)5)2and then to the primaryphosphine complex (RPH2)(W(CO)5). On the basisof DFT calculations, the mechanism most likely involves the additionof H2to the P–W bond, followed by the formationof the radical [RPH-W(CO)5]•by homolysisof the W–H bond. In the case of [PhNHP-W(CO)5],the hydrogenolysis takes place at the P–N bond and ultimatelyproduces the secondary diaminophosphine complex ((PhNH)2PH)(W(CO)5). [ABSTRACT FROM AUTHOR]

Abstract: An organopalladium complex containing orthometalated (R)-(1-(dimethylamino)ethyl)naphthalene as the chiral auxiliary has been used to promote the asymmetric hydroalkoxylation reactions between weak nucleophile methanol and 1,1-bis(diphenylphosphino)ethylene or 1,1-bis(diphenylphosphino)ethylene monoxide in good regio- and stereo-selectivities in the presence of an external base. The major addition product obtained from methanol and 1,1-bis(diphenylphosphino)ethylene monoxide was subsequently isolated in a quantitative yield in its configurationally pure form and characterized by means of two-dimensional rotating-frame nuclear Overhauser enhancement (ROESY) NMR spectroscopy as well as single crystal X-ray diffraction analysis. The enantiomerically pure bis-phosphine monoxide ligand was subsequently liberated in high yield. [ABSTRACT FROM AUTHOR]