Styrene butadiene rubber (SBR) is commonly synthesized from 1,3-butadiene and styrene monomers via two ubiquitous synthetic pathways, by emulsion (ESBR) and solution (SSBR) processes. Emulsion SBR accounts for 70% of the share of the world SBR market but is slowly being taken over by SSBR, as the latter is in high demand for high-performance tires, compatible with polar fillers such as silica for SBR–silica composites. High performance tires provide the benefits of increase in fuel efficiency, low carbon footprints, and high abrasion and better skid resistance properties. ESBR manufacturers are slowly converting their technology into SSBR due to the high demand of the SSBR product. On the other hand, unlike ESBR, functionalized emulsion based SBR (FESBR) can be comparable with SSBR for making high performance tires. FESBR can be synthesized from green eco-friendly emulsion based heterogeneous process similar to ESBR. Synthetic route utilizes various polar reagents such as acrylates, glycidyl methacrylates, acrylonitrile, vinyl carboxylic acid, vinyl sulfonates, vinylic pyridine, fumaric acid, itaconic acid, etc. as third comonomer along with styrene and 1,3-butadiene. FESBR grades are compatible with silica filler and bind via hydrogen and/or chemical bonding with polar filler surface functionality. Bonding between FESBR and silica allows the uniform distribution of silica in polymer matrix via reaction of silica surface hydroxyl groups with polymer functional groups. FESBR-silica composite would give better performance properties in terms of improved rolling resistance, better modulus, tensile strength, better abrasion resistance, and skid resistance similar to SSBR. In the present review, the general introduction of SBR, silica as filler in specialty tire applications, synthetic routes of FESBR, and FESBR–silica composites for high performance tire applications were discussed.

Vorsicht bissige Liganden! Eine Serie von Fluoralkoxy‐funktionalisierten Imidazol‐2‐yliden‐Liganden wurde durch die Alkylierung von einfachen, kommerziell erhältlichen Azolen mit Hexafluorisobutylenoxid synthetisiert. Die Deprotonierung dieser Spezies mit einer starken Base lieferte die freien Carbene, die als dreizähnige Chelatliganden agieren (siehe Schema).

The threefold cross-coupling reactivity of sterically highly demanding bulky triarylbismuths was addressed with task specific Pd–Cu dual catalytic conditions.

An efficient palladium-catalyzed protocol was demonstrated for the chemoselective cross-coupling of functionalized benzylic bromides with triarylbismuth reagents. Under the established conditions, catalyzed by palladium in the presence of K 3 PO 4 base in DMA at 90 uC for 1 h, the threefold arylations using triarylbismuth reagents proceeded smoothly with electronically diverse benzylic bromides. All the coupling reactions furnished the corresponding functionalized diarylmethanes in high yields.