Friedel-Crafts reaction with polyolefins as alkylation reagents and poly(vinyl chloride) as initiator

Transformation of waste plastics into high-value chemicals provides an important solution to mitigate their huge impact on the environment. Polyolefins, including polyethylene and polypropylene, two most produced plastics, are composed of long-chain alkanes and can be potentially applied as alkylation reagents for organic transformations. In this work, we demonstrated that aluminum trichloride in the combination of poly(vinyl chloride), the third most produced and one of the least recycled plastic, can mediate Friedel-Crafts reaction of benzene with polyethylene, polypropylene or the mixture of the two as alkylation reagents. The reaction takes place under mild conditions, selectively producing toluene, ethylbenzene, cumene and n-propylbenzene. As the two major alkylbenzene products, ethylbenzene and cumene, are traditionally produced with ethylene or propene as alkylation reagent, this protocol shows the potential of polyolefins as surrogates for small olefins in organic transformations, offering new opportunities in a sustainable circular economy.