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Carbon dioxide (CO2) has long been recognized as an ideal C1 feedstock comonomer for producing sustainable materials because it is renewable, abundant, and cost-effective. However, activating CO2 presents a significant challenge because it is highly oxidized and stable. A CO2/butadiene-derived δ-valerolactone (EVP), generated via palladium-catalyzed telomerization between CO2 and butadiene, has emerged as an attractive intermediate for producing sustainable copolymers from CO2 and butadiene. Owing to the presence of two active carbon–carbon double bonds and a lactone unit, EVP serves as a versatile intermediate for creating sustainable copolymers with a CO2 content of up to 29 wt % (33 mol %). In this Review, advances in the synthesis of copolymers from CO2 and butadiene with divergent structures through various polymerization protocols have been summarized. Achievements made in homo- and copolymerization of EVP or its derivatives are comprehensively reviewed, while the postmodification of the obtained copolymers to access new polymers are also discussed. Meanwhile, potential applications of the obtained copolymers are also discussed. The literature references were sorted into sections based on polymerization strategies and mechanisms, facilitating readers in gaining a comprehensive view of the present chemistry landscape and inspiring innovative approaches to synthesizing novel CO2-derived copolymers. 

Mono‐ and dianions of 2‐tert‐butyl‐3a²‐azapentabenzo[bc,ef,hi,kl,no]corannulene (1 a) were synthesized by chemical reduction with sodium and cesium metals, and crystallized as the corresponding salts in the presence of 18‐crown‐6 ether. X‐ray diffraction analysis of the sodium salt, [{Na⁺(18‐crown‐6)(THF)₂}₃{Na⁺(18‐crown‐6)(THF)}(1 a²⁻)₂], revealed the presence of a naked dianion. In contrast, controlled reaction of1 awith Cs allowed the isolation of singly and doubly reduced forms of1 a, both forming π‐complexes with cesium ions in the solid state. In [{Cs⁺(18‐crown‐6)}(1 a⁻)]⋅THF, asymmetric binding of the Cs⁺ion to the concave surface of1 a⁻is observed, whereas in [{Cs⁺(18‐crown‐6)}₂(1 a²⁻)], two Cs⁺ions bind to both the concave and convex surfaces of the dianion. The present study provides the first successful isolation and characterization of the reduced products of heteroatom‐containing buckybowl molecules.

 

Mono‐ and dianions of 2‐tert‐butyl‐3a²‐azapentabenzo[bc,ef,hi,kl,no]corannulene (1 a) were synthesized by chemical reduction with sodium and cesium metals, and crystallized as the corresponding salts in the presence of 18‐crown‐6 ether. X‐ray diffraction analysis of the sodium salt, [{Na⁺(18‐crown‐6)(THF)₂}₃{Na⁺(18‐crown‐6)(THF)}(1 a²⁻)₂], revealed the presence of a naked dianion. In contrast, controlled reaction of1 awith Cs allowed the isolation of singly and doubly reduced forms of1 a, both forming π‐complexes with cesium ions in the solid state. In [{Cs⁺(18‐crown‐6)}(1 a⁻)]⋅THF, asymmetric binding of the Cs⁺ion to the concave surface of1 a⁻is observed, whereas in [{Cs⁺(18‐crown‐6)}₂(1 a²⁻)], two Cs⁺ions bind to both the concave and convex surfaces of the dianion. The present study provides the first successful isolation and characterization of the reduced products of heteroatom‐containing buckybowl molecules.