Constructive functionalization of unstrained aryl–aryl bonds has been a fundamental challenge in organic synthesis due to the inertness of these bonds. Here we report a split cross-coupling strategy that allows twofold arylation with diverse aryl iodides through cleaving unstrained aryl–aryl bonds of common 2,2′-biphenols. The reaction is catalysed by a rhodium complex and promoted by a removable phosphinite directing group and an organic reductant such as tetrakis(dimethylamino)ethylene. The combined experimental and computational mechanistic studies reveal a turnover-limiting reductive elimination step that can be accelerated by a Lewis acid co-catalyst. The utility of this coupling method has been illustrated in the modular and simplified syntheses of unsymmetrical 2,6-diarylated phenols and skeletal insertion of phenylene units.

由于这些键的惰性，未过滤的芳基-芳基键的构建官能团化一直是有机合成中的一个基本挑战。在这里，我们报道了一种分裂交叉偶联策略，该策略允许通过裂解常见 2,2′-双酚的未过滤芳基-芳基键与不同的芳基碘化物进行双重芳基化。该反应由铑络合物催化，并由可移除的膦酸盐导向基团和有机还原剂（如四（二甲氨基）乙烯）促进。结合实验和计算机理研究揭示了一个限制周转的还原消除步骤，该步骤可以通过路易斯酸助催化剂加速。这种耦合方法的实用性已经在不对称的 2,6-二芳基酚和苯基单元的骨架插入的模块化和简化合成中得到了说明。