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The synthesis and characterisation (IR, NMR, HR-MS, and X-ray crystallography) of six oxazoline Zn complexes, containing enolate ligands derived from a series of (Z)-1-R-2-(4',4'-dimethyl-2'-oxazolin-2'-yl)-efh-1-en-1-ols (R=[C.sub.6][H.sub.5], [C.sub.6][H.sub.4]-p-N[O.sub.2], [C.sub.6][H.sub.4]-p-O[CH.sub.3], [CF.sub.3], [CH.sub.3], or [CMe.sub.3]) is detailed. All derivatives are air-stable solids of formula Zn[([L.sup.n]).sub.2] and are formed in the presence of the title ligands and [NEt.sub.3]. Reasonable yields (53%-82%) are obtained with the exception of R= [CMe.sub.3] (9%); in this case, by-product formation and high solubility affected complex isolation. Crystallographic characterisation reveals that in all cases the ligands are bound in a [kappa].sup.2]-N, O-bonding motif. Little structural diversity is noted within the series; these complexes are further placed into structural context with related Zn materials containing oxazoline, phenolate, and (or) Schiff base ligands. Key words: oxazoline, coordination complexes, zinc, enolate, X-ray crystal structure, Introduction The naturally occurring Group 12 elements hold a unique position within coordination chemistry due to the overwhelming predominance of the +2 oxidation state. This is, of course, a result [...]

A method for the synthesis of substituted 1,2,4,5-oxadiazaboroles is described, in which hydroxylamines, nitriles, and diarylborinic acids engage in a three-component condensation reaction. The protocol provides access to a substitution pattern that is not readily available through other methods--namely, 2,3-disubstitution, with a tetracoordinate boron center. Structures of representative members of this class of heterocycles were determined by single crystal X-ray diffraction analysis. Key words: boron, condensation, heterocycles, nitriles, Introduction Boron-based heterocycles are of interest from several perspectives, (1) including fundamental studies of structure, bonding, reactivity, and photophysical properties, along with potential applications in material science, (2) catalysis, (3) [...]

The 2-adamantyl (2-Ad) group is a particularly challenging alkyl to install on a transition metal, with the only reported 2-Ad complexes of platinum being those of Pt(II). The question of whether 2-Ad complexes with platinum in the oxidation state +IV can be made and whether they are stable is answered here. The Pt(IV) compound trans-[(bpy)[PtMe.sub.2](2-Ad)I] (bpy = 2,2=-bipyridine) was synthesized via oxidative addition of iodomethane to [(COD)PtMe(2-Ad)] (COD = 1,5-cyclooctadiene) in the presence of bpy. Iodide abstraction with silver triflate (triflate anion, [OTf.sup.-] = [CF.sub.3][SO.sub.3.sup.-]) produced trans-[(bpy)[PtMe.sub.2](2-Ad)(OTf)]. Both complexes were unambiguously characterizedby1DNMR ([.sup.1]H,[.sup.13]C) spectroscopy and X-ray crystallography. Both show evidence for the large steric bulk of the 2-Ad group (through the conformation of the complex adopted) and also for its exceptionally pronounced transinfluence (very long bonds to iodide/triflate trans to adamantyl). Both of the new platinum(IV) adamantyl complexes were extremely stable, even to prolonged heating. Key words: platinum(IV), oxidative addition, adamantane, density functional calculations, trans influence. Le groupe 2-adamantyle (2-Ad) est un group alkyle particulierement difficile a lier a un metal de transition; les seuls exemples connus de complexes de 2-Ad avec le platine sont ceux de Pt(II). Nous abordons dans le present article la question a savoir si les complexes de 2-Ade avec le platine a l'etat d'oxydation +IV peuvent etre fabriques et s'ils sont stables. Nous avons synthetise le complexe de Pt(IV) trans-[(bpy)[PtMe.sub.2](2-Ad)I] (bpy = 2,2=-bipyridine) par addition oxydante de l'iodomethane au [(COD)PtMe(2-Ad)] (COD = 1,5-cyclooctadiene) en presence de bpy. L'abstraction de l'atome d'iode par le triflate d'argent (anion triflate, [OTf.sup.-] = [CF.sub.3][SO.sub.3.sup.-]) a produit le trans-[(bpy)[PtMe.sub.2](2-Ad)(OTf)]. Nous avons caracterise sans equivoque les deux complexes par spectroscopie RMN 1D ([.sup.1]H, [.sup.13]C) et radiocristallographie. Les deux methodes revelent un fort encombrement sterique du groupe 2-Ad (par la conformation qu'adopte le complexe) et egalement une influence trans exceptionnellement marquee (liaisons tres longues entre l'iode ou le triflate et le groupe adamantyle). Les deux nouveaux complexes d'adamantylplatine(IV) etaient extremement stables, meme lorsqu'ils etaient exposes a une chaleur prolongee. [Traduit par la Redaction] Mots-cles : platine(IV), addition oxydante, adamantane, calculs de la fonctionnelle de la densite, influence trans., Introduction The chemistry of platinum alkyls has been a testbed for new organometallic chemistry for over 110 years now. When Pope and Peachey synthesized trimethylplatinum(IV) iodide in 1909, it was [...]

Two coordinate boron cations are rare. Herein we report the synthesis of [RNSiMe2CH2]2BF (R = Dipp 3, 1-Ad 5) (Dipp = C6H3(iPr)2, Ad = C10H15) via the reaction of BF3 with the corresponding dilithiated diamides. Subsequent abstraction of fluoride provided the corresponding borinium salts, [(RNSiMe2CH2)2B][B(C6F5)4] (R = Dipp 6, 1-Ad 8). While the former was generated, the latter proved isolable and was crystallographically characterized. [ABSTRACT FROM AUTHOR]

para-Substitution reactions on C6F5 rings of Lewis acids have been exploited to achieve triply substituted derivatives. The reaction of B(C6F5)3 with P(SiMe3)3 ultimately affords the Lewis acid B(C6F4P(SiMe3)2)31. This species binds Lewis bases affording the adducts LB(C6F4P(SiMe3)2)3 (L = MeCN 2, OPEt33, PMe34, PBu35) and reacts with LiMe to give the salt [Li][MeB(C6F4P(SiMe3)2)3]·3THF 6. It also reacts with H2O to give (L)B(C6F4PH2)3 (L = H2O 7, MeCN 8). In an analogous fashion, [(C6F5)3PF][B(C6F5)4] was converted to [FP(C6F4P(SiMe3)2)3] [B(C6F5)4] 9 and subsequently to [(MeO)P(C6F4PH2)3][B(C6F5)4] 10. [ABSTRACT FROM AUTHOR]

Select triphenyl stannanes bearing either a formally sp2 or sp3 hybridized amine, viz 2-(pyC2H4)SnPh3 (2: py = pyridinyl), 4-(pyC2H4)SnPh3 (3), 2-(pzC2H4)SnPh3 (4: pz = pyrazyl), and Me2N(CH2)3SnPh3 (6), were prepared and characterized by NMR spectroscopy (119Sn, 13C, 1H), and additionally, in the case of 2, by single crystal X-ray diffraction. Bromination of 2 to yield 2-(pyC2H4)SnPhBr2 (8) was achieved in good yield. X-ray crystallographic analysis of 8 revealed two unique molecules with 5-coordinate Sn centers featuring Sn-N distances of 2.382 (5) and 2.363 (5) Å, respectively. The calculated structures of the non- and hypercoordinating C,N-stannanes (1–9) were in good agreement with available crystallographic data. The relative stabilities of hyper- and non-hypercoordinating conformers obtained from conformational sampling were determined by comparison with reference conformers and by natural bond orbital (NBO) energetic analyses. Reduction of 8 to the dihydride species, 2-(pyC2H4)SnPhH2 (9), and subsequent conversion to the polystannane, -[2-(pyC2H4)SnPh]n- (15), by transition metal-catalyzed dehydropolymerization was also achieved. Evidence for the decomposition of 15 into a redistributed distannoxane, {2-(pyC2H4)SnPh2}2O (16), was also observed. [ABSTRACT FROM AUTHOR]

Poly(3‐hexylthiophene) (P3HT) is a well‐studied conjugated polymer; however, the end‐group functionalization of these polymers is limited by fundamental synthetic challenges. Generally, end‐capping agents are used to terminate the Kumada catalyst transfer polycondensation (KCTP) to install functional end‐groups at the propagating chain end. In this work, it is shown that P3HT can be prepared with a novel SNAr‐active external initiator, followed by end capping to afford heterobifunctional end‐groups that exhibit orthogonal chemical reactivity. This orthogonal chemistry can be leveraged in sequential "click"‐type reactions to ultimately achieve the synthesis of triblock copolymers. More specifically, it is shown that the synthesis of a new pentafluorophenyl initiator allows one to append this readily functionalized group at the initiating end during P3HT synthesis. After reaching the desired degree of polymerization, an ethynyl group is incorporated at the polymer terminus using an end‐capping Grignard reagent. Critically, this heterobifunctional P3HT allows for both orthogonal para‐fluoro thiol reactions, a subset of nucleophilic aromatic substitution (SNAr), and copper‐catalyzed alkyne‐azide cycloadditions (CuAAC). The efficacy of this heterobifunctional polymer design is demonstrated by assessing sequential "click" reactions with different nonconjugated polymer blocks to either end of the P3HT polymer block. [ABSTRACT FROM AUTHOR]