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In the presence of a catalytic amount of heavier tetrylene dichlorides, an allenic diborene 1 undergoes a 1,3-hydrogen shift to afford a terminal diborene 2, which can be deemed a boron analogue of vinylidene dication stabilized by Lewis bases. X-ray diffraction analysis and computational studies revealed that 2 involves a conjugative interaction between the C= C and B=B π-orbitals. The reaction of 2 with ZnBr[sub 2]afforded the corresponding isolable complex 3, in which two boon centers coordinate to the Zn atom asymmetrically. [ABSTRACT FROM AUTHOR]

1-Phenyl-2-vinyl-3,4-dimethylphosphole(4) was prepared from the corresponding 2-carboxaldehydevia a Wittig reaction. The reaction of its P-W(CO)5complex 5with [PhP-W(CO)5] selectively takes place atthe vinyl double bond and gives the corresponding phosphirane 6as a mixture of two diastereomers. The reaction of 4with N-phenylmaleimide involves the phospholedienic system and gives the [4 + 2] 7-phosphanorbornene cycloadduct 7. The reaction of 5with dimethyl acetylenedicarboxylateeither takes place at the phosphole dienic system and leads to thevinyl phthalate 10with loss of the phosphorus bridgeor involves the double bonds of the vinyl and one phosphole groupto give the [4 + 2] cycloadduct 9, which is oxidizedin situ to give 11with two epoxides and one ketone functionality.The products 6, 7, 9, and 11were characterized by X-ray crystal structure analysis. [ABSTRACT FROM AUTHOR]

Thereaction of 1-phenyl-2-lithio-3,4-dimethylphosphole with W(CO)6at −90 °C followed by methyl triflate at roomtemperature gives the complex [(phosphol-2-yl)methoxycarbene]pentacarbonyltungsten(1). This complex reacts with sulfur to give the correspondingcomplex [methyl (phosphol-2-yl)thiocarboxylate]pentacarbonyltungsten(2), in which tungsten has migrated from the carbeneto phosphorus. The reaction of 3with alkynes at 90 °Cgives the corresponding phospholene-annelated cyclopentenones 5without the need for a nickel catalyst. In one case, anintermediate vinylketene rearranges by an intramolecular Diels–Alderreaction to give the tricyclic compound 6. All of theproducts have been characterized by X-ray crystal structure analysis. [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]

This paper reports the size-exclusion properties of nanoporous films derived from polystyrene-poly(methylmethacrylate) diblock copolymers (PS-b-PMMA) for biomacro-molecules. These properties were assessed by measuring cyclic voltammetry of ferritin (12 nm in diameter) adsorbed onto recessed nanodisk-array gold electrodes (RNEs) fabricated from the nanoporous films having different effective pore diameters and surface functionalities. RNEs having 20-nm-diameter nanopores modified with a poly(ethylene glycol) (PEG) layer showed the redox currents of ferritin after their immersion in a ferritin solution (5 mg/mL) for longer than 2 h. The currents originated from the direct electron transfer reaction of ferritin molecules immobilized on the underlying gold surface as a result of their penetration through the 20-nm-diameter nanopores. The PEG modification of the nanopore surface was required for the penetration of ferritin, probably because it reduced the nonspecific adsorption of ferritin to the nanopore surface. In contrast, no redox current of ferritin was observed for RNEs having PEG-modified 15-nm-diameter nanopores after their immersion in the ferritin solution for 12 h, indicating the size-exclusion of ferritin from the 15-nm nanopores. The distinct size-exclusion properties of the PS-b-PMMA-derived nanoporous films reflect their uniform diameters and shapes and will provide a means for fabricating separation membranes for biomolecules with high size-based selectivity. [ABSTRACT FROM AUTHOR]

The reaction of the base-stabilizedsilyliumylidene triflate [LSi(DMAP)]OTf(1·OTf; L = PhC(NtBu)2, DMAP = 4-dimethylaminopyridine) with [Rh(cod)Cl]2and W(CO)5THF afforded [{L(DMAP)Si}2{μ-Rh(μ-Cl)2Rh(cod)}](OTf)2(2) and [L(DMAP)Si→W(CO)5]OTf (3), respectively. Their crystal structures determined by X-ray crystallography showthat the silyliumylidene cation acts as a two-electron donor coordinatingto the rhodium and tungsten atoms. [ABSTRACT FROM AUTHOR]

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 stereoelectronic properties ofpalladium(II) and platinum(II)complexes containing ortho-metalated (1-(diphenylphosphino)ethyl)naphthalenewere examined by X-ray crystallography in the solid state and by NMRspectroscopy in solution. The studies revealed that the aromatic carboninduced a significantly stronger electronic trans-influence than the phosphorus donor within the same five-memberedchelate. Both the organopalladium and organoplatinum chelate complexeswere formed with classical hard oxygen and soft phosphorus donor atoms.Computational studies further confirmed the observations in the solidstate and solution that the C–metal bond in the transC–Pt–O moiety has a stronger π-character thanthat in the transC–Pt–P moiety. Bothorganometallic units are efficient catalysts for the asymmetric P–Haddition reaction. They showed almost identical efficiency in dichloromethane,but their reactivity in THF is markedly different. [ABSTRACT FROM AUTHOR]

A novel racemic tertiary amine, 1-(2,5-diisopropylphenyl)-N,N-dimethylethanamine, was synthesizedfrom 2,5-diisopropylbenzaldehyde via a multistep approach in highoverall yield. The ortho palladation of this ligand was found to besensitive to the reaction conditions and the palladating reagentsemployed. The metal complexation process could thus generate a cyclopalladatedcomplex in high yield, lead to an unexpected N-demethylated aminepalladium(II) complex, or both. Both products have been isolated andcharacterized crystallographically in the solid state and spectroscopicallyin solution. The racemic cyclopalladated complex could be efficientlyresolved via the formation of (S)-prolinato derivatives.The absolute stereochemistries of the resolved diastereomeric complexeswere determined by single-crystal X-ray crystallography in the solidstate and by 1H–1H rotating frame Overhausereffect (ROESY) NMR spectroscopy in solution. An evaluation of thesterically hindered resolved cyclopalladated units as chiral auxiliarieswas conducted in the endo-cycloaddition reaction between 3,4-dimethyl-1-phenylphosphole(DMPP) and ethyl vinyl ketone. The two expected phosphanorborneneadducts were generated with moderate stereoselectivity. [ABSTRACT FROM AUTHOR]

2-Phosphaphenol (L) forms unusualcomplexes with copper and gold halides. With CuCl, a dimeric [L2CuCl]2complex is observed with L acting both asη1-P terminal and μ2-P bridgingligand and a copper–copper short contact of 2.549 Å. Withcopper bromide, a distorted infinite chain [L2CuBr]nis formed, whereas with copper iodide, thezigzag chain [L2CuI]nis observed.The phosphaphenol acts as a terminal ligand coating the CuX molecularwires. With gold chloride, a dimeric [LAuCl]2complex isformed, which is held by an aurophilic interaction at 3.132 Å. [ABSTRACT FROM AUTHOR]

Thereactivity of the tin(II) 1,3-benzodi(thiophosphinoyl)methanediidecomplex [{μ-1,3-C6H4(PhPS)2C}Sn]2(1) toward GaCl3, GeCl4, and ZnEt2is described. The reaction of 1with 1.7 equiv of GeCl4in CH2Cl2at room temperature afforded [1,3-C6H4(PhPS)2C(GeCl3)SnCl]2(2). Treatment of 1with 1.7 equiv of ZnEt2in refluxing toluene afforded [{1,3-C6H4(PhPS)2CSnEt2}(μ-ZnS)]2(3). Compound 1also reacted with 1.7 equiv of GaCl3in CH2Cl2to afford [1,3-C6H4(PhPS)2C(Sn)(GaCl3)] (4). Compounds 2–4have been characterizedby NMR spectroscopy and X-ray crystallography. [ABSTRACT FROM AUTHOR]

The monomeric ortho-platinated complexes[Pt{R1CH(1-C6H4)NMe2-C,N}{Ph2PCCR2}Cl] (R1= Me, Et; R2= Me, Ph) with trans-N,Pgeometries were obtained regiospecificallyfrom the reaction between the dimeric [Pt2(μ-Cl)2{R1CH(1-C6H4)NMe2-C,N}2] and the correspondingalkynylphosphines in high yields. The phosphine complexes are highlystable in the solid state and in solution. However, in the presenceof additional Pt(II) ions, an intramolecular coupling reaction occurredin which a new carbon–carbon bond was formed between the aromaticγ-carbon of the ortho-platinated chiral phenylamineand the α-carbon of the (Ph2P)–CαCβ–(R2) ligand. The (Ph2P) moiety migrated to the neighboring β-carbon duringthe coupling reaction. By the judicious selection of the substituentson the alkynylphoshine along with deliberate introduction of selectedchirality on the ortho-platinated phenylamine, thecoupling reaction and the (Ph2P) migration were found toproceed via an associative intramolecular mechanism that involvesa Pt-vinylidene intermediate. [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]

An organopalladium complex containing ortho-metalated (R)-(1-(dimethylamino) ethyl)naphthalene as the chiral auxiliary has been used to promote the asymmetric hydrophosphination reaction between diphenylphosphine and phenyldi[(Z)-prop-1-enyl]phosphine in high regio- and stereoselectivity under mild conditions. The hydrophosphination reaction generated only two diastereomers in a ratio of 1:1. The two hydrophosphination products contained both phosphorus and carbon stereogenic centers and were subsequently isolated by fractional crystallization. Their absolute stereochemistries were analyied by X-ray crystallography. The naphthylamine auxiliary could be removed chemoselectively from the template products by treatment with concentrated hydrochloric acid to form the corresponding optically pure neutral dichloro complexes. Subsequently, the dichioro complexes underwent ligand displacement with aqueous cyanide to generate the optically pure diphosphine ligands in high yields. [ABSTRACT FROM AUTHOR]

A novelBN-fused coronene derivative 1,5,9-triaza-2,6,10-triphenylboracoronene(1) has been successfully synthesized in one step from2,3,6,7,9,10-hexamethoxy-1,5,9-triamino-triphenylene. Compound 1has been investigated using photophysical, electrochemical,and molecular simulation methods. Interestingly, three phenyl groupsat B centers in compound 1can be replaced by hydroxylunits stepwise through hydroxylation in wet organic solvents, leadingto changes in the packing and physical properties. [ABSTRACT FROM AUTHOR]

Thereaction of a terminal alkyne (RCCH) and 2-aminopyridine (R′C5NH3NH2) with the dinuclear species [Cp*IrCl2]2afforded the cationic aminocarbene derivativesCp*Ir(Cl)[ C(CH2R)NHC5NH3R′] via a hydroamination and a ligand substitution. The reactionpathway has been examined through computational studies. [ABSTRACT FROM AUTHOR]

The reaction of [CH2(PPh2S)2](1) with 2 equiv of MeLi in Et2O followedby addition of 0.5 equiv of SiCl4afforded the base-stabilized2-silaallene [(PPh2S)2CSiC(PPh2S)2] (2). It has been characterized by X-ray crystallography,NMR spectroscopy, and theoretical studies. The results show that compound 2comprises a C¯–Si2+–C¯ylidic skeleton with a negative charge at the Cmethanediideatoms and two positive charges at the Si atom.The reaction of 2with excess PriNCNPriin refluxing toluene gave the thiophosphinoyl-stabilizedsilene [(PPh2S)2C–Si+(NPri)2CC(PPh2S)2] (3). [ABSTRACT FROM AUTHOR]

The synthesis of a tin(II) 1,3-benzobis(thiophosphinoyl)methanediidecomplex and its reactions with aluminum compounds are reported. Thereaction of the 1,3-benzodiphosphole disulfide [1,3-C6H4(PhPS)2CH2] (4)with [Sn{N(SiMe3)2}2] in refluxingtoluene afforded the tin(II) 1,3-benzobis(thiophosphinoyl)methanediide[{μ-1,3-C6H4(PhPS)2C}Sn]2(5). The X-ray crystal structure of 5shows that it has a 1,3-dimetallacyclobutane structure.The reaction of 5with 1 equiv of AlCl3inCH2Cl2afforded [1,3-C6H4(PhPS)2C(Sn){Sn(SPPh)2C(AlCl3)-1,3-C6H4}] (6). The reactionproceeds via an insertion of a AlCl3molecule into oneof the Sn–C bonds in 5. The reaction of 5with 2 equiv of AlCl3in CH2Cl2afforded [1,3-C6H4(PhPS)2C(Sn)(AlCl3)] (7). The reaction appearsto proceed via the formation of compound 6, which thenundergoes an insertion with another AlCl3molecule to formcompound 7. The transmetalation reaction of 5with 2 equiv of AlMe3in CH2Cl2afforded [1,3-C6H4(PhPS)2CAlMe]2(8), which contains a terminal Cmethanediide–Al bond. [ABSTRACT FROM AUTHOR]

A palladacycle-catalyzed diastereo- and enantioselectivestepwisedouble hydrophosphination of bis(enones) with PhPH2hasbeen developed, allowing intermolecular construction of chiral tertiarybulky P-heterocycles in one pot in high yields. A catalytic cyclefor the reaction is proposed as well. [ABSTRACT FROM AUTHOR]

A chiral palladacycle-promoted enantioselective asymmetrichydrophosphinationof substituted methylidenemalonate esters using diphenylphosphinethat provides direct access to chiral tertiary phosphines is reported.Screening of three easily accessible C,N and C,P palladacycles ascatalysts for this synthetic scenario provided insights into criticalfactors in catalyst design that influence the activation and stereochemistryin Pd(II)-catalyzed asymmetric P–H addition reactions involvingsuch activated substrates. [ABSTRACT FROM AUTHOR]

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]

The organoplatinum complex containing ortho-metalaled (R)-(1-(dimethylamino)ethyl)-naphthalene as the chiral auxiliary has been used efficiently to promote the asymmetric [4 -1-2] Diels-Alder reaction between diphenylvinyiphosphine and 3-diphenylphosphinofuran to generate two chelating diphosphine endocycloaddticts in the ratio 17:1. The absolute configurations of the three newly generated stereocenters have been assigned by single-crystal X-ray analysis. [ABSTRACT FROM AUTHOR]

A newapproach toward ferrocenyl phosphapalladacycle construction from achiralenones via asymmetric hydrophosphination and subsequent diastereoselectiveC–H activation is described. Its catalytic efficacy towardC–C bond formation is subsequently illustrated. [ABSTRACT FROM AUTHOR]