Palladium Alkynylation Catalyst

Mild-condition selective cleavage

This catalyst enables selective cleavage of lignin-related aryl ether bonds under ambient conditions via alkynylation, directly affording valuable alkynes without harsh acids, bases, or extreme temperatures.

Kaitong, Zeng · Fanghua, Mao · Jiang, Huanfeng · Li, Jianxiao

Catalysis Science and Technology 2026

Specifications

Yield

{'zh': '94', 'en': '94'} %

Substrate scope

{'zh': '40', 'en': '40'}

Catalyst recycling runs

{'zh': '6', 'en': '6'}

Catalyst loading

{'zh': '1', 'en': '1'} mol%

Advantages

No strong acids/bases

The reaction runs in the basic ionic liquid [Apmim]BF4, which serves as both solvent and base, eliminating the need for conventional strong bases.

Ambient conditions

The reaction proceeds efficiently under ambient conditions, without elevated temperatures, high pressures, or inert atmosphere.

Broad FG tolerance

Forty examples demonstrate excellent functional group compatibility, accommodating a wide range of substituted diaryl ethers and terminal alkynes.

Recyclable catalyst

The catalyst and ionic liquid system can be recycled six times with essentially retained activity, reducing cost and waste.

Applications

• Lignin depolymerization：Directly converts aryl ether linkages in lignin into aryl internal alkynes via selective cleavage and valorization.
• Biomass valorization：Upgrades aryl ether units in waste biomass into high-value alkynes, enhancing overall value.
• Green catalysis：Employs a recyclable ionic liquid and palladium catalyst under ambient conditions for green synthesis.
• Polymer upcycling：Degrades polyphenylene oxide waste into small-molecule alkynes, enabling upcycling of waste polymers.