In contrast to the many methods of selectively coupling olefins, few protocols catenate saturated hydrocarbons in a predictable manner. We report here the highly selective carbon-hydrogen (C-H) activation and subsequent dehydrogenative C-C coupling reaction of long-chain (>C(20)) linear alkanes on an anisotropic gold(110) surface, which undergoes an appropriate reconstruction by adsorption of the molecules and subsequent mild annealing, resulting in nanometer-sized channels (1.22 nanometers in width). Owing to the orientational constraint of the reactant molecules in these one-dimensional channels, the reaction takes place exclusively at specific sites (terminal CH(3) or penultimate CH(2) groups) in the chains at intermediate temperatures (420 to 470 kelvin) and selects for aliphatic over aromatic C-H activation.

Wasserstoffspaltung: Die Reaktion des Zirconiumkomplexes A mit dem Piers‐Boran [HB(C6F5)2] liefert den ungewöhnlichen Borylalkin‐Zirconocenkomplex B, der Diwasserstoff aktivieren kann und dabei den doppelt Hydrido‐verbrückten Alkinzirconiumkomplex C ergibt.

The reaction of η(2)-iminozirconocene chloride complexes with trimethylsilylethynyl lithium leads to rapid C-C coupling at room temperature to yield the corresponding five-membered aza-zirconacycloallenoids. Such compounds were also obtained by trapping of in situ generated zirconocene with alkynyl imines.

Ring‐opening metathesis polymerization (ROMP)‐derived poly(oxanorbornene imide)s bearing bay‐linked mono‐alkoxy‐M1 and 1,7‐di‐alkoxy M2 functionalized perylene diimides (PDIs) were synthesized using Grubb's third (G3) and Hoveyda‐Grubbs second generation (HG2) ruthenium‐alkylidene metathesis initiators. The mono‐alkoxy‐derived PDI‐based non‐ladderphane polymer polyM1 displayed 67% to 77% of the trans olefin content in the polymer chain depending on the initiator used for the polymerization. When using the symmetrical 1,7‐di‐alkoxy‐derived PDI‐based polymer polyM2 having the ladderphane type‐structure, this displayed a significant amount of cis and trans olefin contents in the polymer chains, irrespective of the type of initiators used for the polymerization. ROMP of both monomers M1 and M2 proceeded in a well‐controlled manner with a linear dependence of molecular weight on the monomer/initiator ratio using G3 as initiator. Optical properties of the ladderphane‐based polyM2 and non‐ladderphane‐based polyM1 were characterized in both solution and the film state. X‐ray diffraction (XRD) analysis for all the polymers showed significant π‐stacking in the thin film state with ordered molecular packing and closer values of d‐spacing for both polyM1 and polyM2. Film morphology examined by AFM elucidated homogenous smooth polymer surface for both polymers in general, but with some irregularities observed for polyM1. In addition, CV analysis revealed both polymers could be good candidates as electron‐accepting materials, with excellent film‐forming ability, and thermal stability.

Treatment of a [(trimethylsilylethynyl)alkenyl]ZrCp2 complex with Piers' borane [HB(C6F5)2] resulted in the clean formation of the Zr/B complex [η(2)-(C6F5)2B-C≡C-SiMe3]ZrCp2 (3). This compound shows some unique reaction patterns. With a variety of typical donor ligands (carbon monoxide, an isonitrile, a nitrile, THF-d8,) it forms the respective adducts 5 (four examples characterized by X-ray diffraction). Toward terminal alkynes (RC≡CH) compound 3 behaves as a Zr(II) metal Lewis base/boron Lewis acid frustrated Lewis pair (FLP) and undergoes typical regioselective 1,2-Zr/B addition reactions to yield the metallaheterocyclic products 7 (four examples characterized by X-ray diffraction). Compound 3 also undergoes characteristic 1,4-Zr/B FLP addition to a silyl-substituted conjugated enyne (to give 9) and also to 1,4-bis(trimethylsilyl)butadiyne to yield a metallacyclic butatriene derivative 10 (both 9 and 10 were characterized by X-ray diffraction). Eventually, compound 3 reacted with mes2P-C≡CH to give the metallacycloallenoid product 15, which was probably formed by means of 1,2-Zr/B FLP addition followed by alkynyl shift from boron to zirconium and reductive coupling. Treatment of 3 with tolane gave the closely related zirconacycloallenoid complex 16 by carbon carbon coupling. Both the products 15 and 16 were characterized by X-ray diffraction.