Insights into substitution strategy towards thermodynamic and property regulation of chemically recyclable polymers.

The development of chemically recyclable polymers serves as an attractive approach to address the global plastic pollution crisis. Monomer design principle is the key to achieving chemical recycling to monomer. Herein, we provide a systematic investigation to evaluate a range of substitution effects and structure-property relationships in the ɛ-caprolactone (CL) system.

Highly Reactive Cyclic Carbonates with a Fused Ring toward Functionalizable and Recyclable Polycarbonates.

Monomer design plays an important role in the development of polymers with desired thermal properties and chemical recyclability. Here we prepared a class of seven-membered ring carbonates containing -cyclohexyl fused rings. These monomers showed excellent activity for ring-opening polymerization (ROP) with turnover frequency (TOF) up to 6 × 10 h and catalyst loading down to 50 ppm, which yielded high-molecular-weight polycarbonates ( up to 673 kg/mol) with great thermostability ( > 300 °C).

Manganese(iii)-promoted tandem phosphinoylation/cyclization of 2-arylindoles/2-arylbenzimidazoles with disubstituted phosphine oxides.

A simple and practical method for the synthesis of phosphoryl-substituted indolo[2,1-a]isoquinolin-6(5H)-ones and benzimidazo[2,1-a]isoquinolin-6(5H)-ones through manganese(iii)-promoted tandem phosphinoylation/cyclization of 2-arylindoles or 2-arylbenzimidazoles with disubstituted phosphine oxides was developed. In this transformation, new C-P bond and C-C bond were constructed simultaneously under silver-free conditions, exhibiting a broad substrate scope. It was noted that not only diarylphosphine oxides but also dialkyl and arylalkyl-phosphine oxides were compatible with the conditions.

Electrochemical dehydrogenative cross-coupling of xanthenes with ketones.

A new external oxidant-free electrochemical dehydrogenative cross-coupling of xanthenes and ketones for the preparation of functionalized 9-alkyl-9H-xanthenes was developed. This method enables the formation of a new C(sp)-C(sp) bond through release of H as the major byproduct at room temperature, and features mild conditions, high atom economy, excellent functional-group tolerance, scalability and facile applications in pharmaceutical chemistry.

Copper-catalyzed C-H [3 + 2] annulation of N-substituted anilines with α-carbonyl alkyl bromides via C(sp)-Br/C(sp)-H functionalization.

A copper-catalyzed C-H [3 + 2] annulation of N-substituted anilines with α-carbonyl alkyl bromides for the synthesis of 3,3'-disubstituted oxindoles is developed. Tandem C-H cycloamidation reactions of various α-carbonyl alkyl bromide derivatives including tertiary-α-bromoalkyl ketone esters, malonic esters and cycloalkanes, with N-aryl or alkyl substituted anilines, can be performed using this system, affording a vast array of valuable 3,3'-disubstituted oxindoles in moderate to good yields.

Silver-mediated oxidative 1,2-alkylesterification of styrenes with nitriles and acids via C(sp)-H functionalization.

A new silver-mediated 1,2-alkylesterification of alkenes with nitriles and acids promoted by a catalytic amount of nickel catalyst for producing acyloxylated nitriles has been developed via a C(sp)-H functionalization process. By employing the NiI and AgCO catalytic systems, the method features broad substrate scope with respect to carboxylic acids, including linear alkyl acids, cyclic acids, aryl acids and amino acids.

Transition-metal- and oxidant-free directed anodic C-H sulfonylation of N,N-disubstituted anilines with sulfinates.

A new, practical directed anodic C-H sulfonylation of N,N-disubstituted anilines with sodium sulfinates for producing o- or p-amino arylsulfones and diarylsulfones is described. Employing the anodic strategy, the reaction proceeds efficiently under mild (room temperature) and transition-metal- and chemical oxidant-free conditions, and enables the formation of C-S bonds via directed activation of ortho- or para-C-H bond to the amino group with broad substrate scope and excellent site selectivity.

A metal- and oxidizing-reagent-free anodic para-selective amination of anilines with phenothiazines.

A highly para-selective amination of anilines with phenothiazines for producing various functionalized 10-aryl-10H-phenothiazines is reported. The oxidative amination reaction proceeds electrochemically at room temperature, thereby avoiding the use of metals and oxidizing reagents with excellent functional group tolerance and broad substrate scope.