Palladium‐Catalyzed Long‐Range Isomerization of Aryl Olefins

Abstract

Long-range olefin isomerization could lead to the remote functionalization of hydrocarbon chains, which is advantageous with regards to atom-, step-, and redox economy. However, present methodologies for long-range olefin isomerization are mainly focused on heteroatom directed remote olefin migration; studies using aryl groups as the directing group are limited. The limited examples either utilize aryl olefins with special substituted groups on a benzene ring, or use elaborately optimized ligands or co-catalysts to accelerate the isomerization. A more simple catalytic system for general aryl olefins, without the need for special ligands or co-catalysts, was to be developed. Herein, we report a Pd-catalyzed long-range olefin isomerization (up to 15 units) for general aryl olefins via a 1,2-hydrogen shift mechanism. This methodology provides a simple pathway to long-range olefin isomerization without the participation of special ligands or co-catalysts.

Commodity Rubber Material with Reversible Cross-linking Ability: Application of Boroxine Cross-links to Ethylene-Propylene Rubber

“…The obtained crude product was purified with column chromatography (hexane 100%) to give 2.37 g (49%) of 4-bromo-1-(5-hexenyl)benzene as a colorless solid. The spectral data was identical to the previously reported data …”

“…The spectral data was identical to the previously reported data. 35 In a 100 mL two-necked flask, magnesium turnings (221 mg, 9.1 mmol) were placed in the flask and suspended to THF (10 mL). A solution of 4-bromo-1-(5-hexenyl)benzene (1.82 g, 7.6 mmol in 7 mL of THF) was added dropwise, and the mixture was stirred for 40 min.…”

Bis(pentafluorophenyl)borane-catalyzed E-selective isomerization of terminal alkenes to internal alkenes

“…This year, the groups of Yang, Wu, and Zhang reported a palladium-catalyzed long-range isomerization of aryl alkenes, which is of interest regarding the remote functionalization of these substrates. 10 The aryl group acts as a directing group that provides a thermodynamic driving force for the formation of conjugated aryl alkenes. We have now investigated whether such long-range isomerization of arylalkenes can also be catalyzed by HB(C 6 F 5 ) 2 .…”

Structural Design of Single‐Atom Catalysts for Enhancing Petrochemical Catalytic Reaction Process

“…Isomerization of aromatic hydrocarbons and their derivatives includes functional group isomerization as well as isomerization of branched alkanes and alkenes. [39,40] Coupling isomerization reactions with complex decomposition reactions enables the conversion of homogeneous feedstocks into complex product mixtures with specific and adjustable properties. [41] Various catalysts are employed in the isomerization process, often limited to catalyzing specific isomerization reactions.…”