The hydrogenolysis of C–C bonds is one of the most important processes in the petroleum industry. These transformations typically rely on heterogeneous catalysts and take place at high temperatures and high pressures with limited selectivity. Employing homogeneous transition metal catalysts, while allowing the hydrogenolysis of C–C bonds to proceed under much milder conditions, is only suitable for substrates containing strained C–C bonds or directing groups. Here we report that a borenium complex can catalyse the selective hydrogenolysis of unstrained C(aryl)–C(alkyl) bonds of alkylarenes in the absence of directing groups at ambient temperature, affording the corresponding alkanes and arenes. Mechanistic studies suggest a reaction pathway that involves a synergistic activation of dihydrogen by the borenium complex and alkylarenes, followed by retro-Friedel–Crafts reaction to cleave the C(aryl)–C(alkyl) bonds. The synthetic utility of this protocol is demonstrated by the conversion of post-consumer polystyrene into valuable benzene and phenylalkanes with mass recovery rates above 90%.

C-C键的氢解是石油工业中最重要的过程之一。这些转化通常依赖于多相催化剂，并在高温高压下发生，选择性有限。使用均相过渡金属催化剂，同时允许 C-C 键的氢解在更温和的条件下进行，仅适用于含有应变 C-C 键或定向基团的底物。在这里，我们报道硼配合物可以在环境温度下在没有定向基团的情况下催化烷基芳烃的无应变 C(芳基)-C(烷基)键的选择性氢解，从而提供相应的烷烃和芳烃。机理研究表明，反应途径涉及硼络合物和烷基芳烃对二氢的协同活化，随后进行逆弗瑞德-克拉夫茨反应以裂解 C(芳基)-C(烷基)键。通过将消费后聚苯乙烯转化为有价值的苯和苯烷烃，质量回收率超过 90%，证明了该协议的综合效用。