Being not prone to aging and possessing high C4/C1 selectivity, new tricyclononene polymers bearing (AlkO)3Si side groups are prospective materials for hydrocarbon mixture separation.

A highly efficient solvent‐free protocol for the Buchwald–Hartwig amination of (hetero)aryl halides by secondary amines was developed. The reaction is mediated by a Pd(OAc)2/RuPhos catalytic system in air. Various (hetero)aryl halides were coupled with diaryl, alkyl–aryl, and dialkylamines in good to excellent yields (51 examples, 50–99 % yield).

Stable negative ions containing up to sixteen silicon atoms have been measured by mass spectromettry in RF power-modulated silane plasmas for amorphous silicon deposition. These hydrogenated silicon cluster ions reach much higher masses than the positive ions, which have no more than six silicon atoms. This supports the view that negative ions are the precursors to particulate formation in silane plasmas. The time-dependent fluxes d positive and negative ions from the plasma are shown with a 5 p s time resolution. Possible cluster reaction sequences are discussed and the effect of visible light on the negative ion signal i s commented upon.

We studied the addition polymerization of readily available bifunctional norbornene derivatives, 5-alkylidene-2-norbornenes, in the presence of modified Pd complexes with N-heterocyclic carbene ligands activated by borates. The Pd−N-heterocyclic carbene complex/phosphine/borate systems selectively catalyze the addition polymerization of 5methylene-2-norbornene and 5-ethylidene-2-norbornene with the participation of the endocyclic norbornene double bond, whereas the exocyclic double bond remained intact. The catalysts exhibited extremely high activity and durability: the activity was higher than 1 × 10 8 g polymer / (mol Pd •h) and some catalysts were active at a very high monomer/Pd molar ratio of 2 × 10 7 or at a Pd complex concentration of 5 × 10 −6 mol %. The structure−catalytic activity relationships were established for Pd−N-heterocyclic carbene complexes: the Pd complexes bearing five-membered heterocyclic rings and/or less sterically hindered aryl groups at nitrogen atoms in carbene ligands exhibited the highest activity. The polymerization can be performed in an atmosphere of air and in wet solvents. The resulting polymers are amorphous and high-molecular-weight products consisting of rigid saturated main chains and reactive side groups. Thus, they can be considered as promising intermediates in the production of polymeric materials with high glass-transition temperatures and desired properties by targeted modifications.

A new type of eight-membered ring N-heterocyclic carbene (NHC) bearing a rigid naphthalene moiety in the backbone is reported for the first time. Stereoelectronic properties of 4,5-dihydro-1H-naphtho[1,8-ef][1,3]diazocin-3(2H)-ylidene (NaphtDHD) and smaller ring NHCs were theoretically studied at the DFT level. Amidinium salts were prepared from corresponding amidines and dibromides. Free carbene NaphtDHD-Dipp (Dipp = 2,6-diisopropylphenyl) was generated in solution by treatment of the corresponding salt with LiHMDS. It is stable in solution at low temperatures, while decomposing rapidly at room temperature. Silver(i) and copper(i) complexes were synthesized and structurally characterized in the solid state. The copper(i) complex [(NaphtDHD-Mes)CuBr] (Mes = mesityl, 2,4,6-trimethylphenyl) exhibits high catalytic activity in alkyne-azide cycloaddition (CuAAC) reaction under solvent-free conditions.

Dedicated to the memory of academician N. S. Zefirov.Abstract: Solvent-free protocols for palladium-catalyzed stannylation of aryl halides, Stille cross-coupling, and one-pot, twostep stannylation/Stille cross-coupling (SSC) are reported for the first time. (Het)aryl halides bearing acceptor, donor, as well as sterically demanding substituents are stannylated and/or coupled in high yields. The reactions are catalyzed by conventional palladium(II) acetate/PCy 3 [Pd(OAc) 2 /PCy 3 ] under air, using avail-

A series of Pd/NHC species undergoes R–NHC coupling reaction forming catalytically active NHC-free complexes and/or colloidal Pd nanoparticles.

Solvent‐free protocols for Miyaura borylation and the one‐pot, two‐step homocoupling of aryl halides are reported for the first time. Bis(dibenzylideneacetone)palladium(0) [Pd(dba)2] is an optimal source of palladium for Miyaura borylation, while for one‐pot two‐step homocoupling palladium(II) acetate [Pd(OAc)2] gives highest yields. Aryl bromides are coupled most efficiently using the DPEphos ligand. Chlorides are coupled using XPhos. The developed protocols are robust, versatile and easily reproducible on a large scale.magnified image