Copper-Catalyzed Suzuki–Miyaura Coupling of Arylboronate Esters: Transmetalation with (PN)CuF and Identification of Intermediates

An efficient CuI-catalyzed Suzuki–Miyaura reaction was developed for the coupling of aryl- and heteroarylboronate esters with aryl and heteroaryl iodides at low catalyst loadings (2 mol %). The reaction proceeds under ligand-free conditions for aryl–heteroaryl and heteroaryl–heteroaryl couplings. We also conducted the first detailed mechanistic studies by synthesizing [(PN-2)­CuI]2, [(PN-2)­CuF]2, and (PN-2)­CuPh (PN-2 = o-(di-tert-butylphosphino)-N,N-dimethylaniline) and demonstrated that [(PN-2)­CuF]2 is the species that undergoes transmetalation with arylboronate esters.本研究开发了一种高效的碘化亚铜（CuI）催化铃木-宫浦偶联反应（Suzuki–Miyaura reaction），可在低催化剂负载量（2 mol%）下实现芳基硼酸酯、杂芳基硼酸酯与芳基碘化物及杂芳基碘化物之间的偶联。针对芳基-杂芳基以及杂芳基-杂芳基的偶联过程，该反应可在无配体条件下顺利进行。我们还通过合成[(PN-2)­CuI]₂、[(PN-2)­CuF]₂及(PN-2)­CuPh（其中PN-2为邻-(二叔丁基膦基)-N,N-二甲基苯胺），开展了首次详尽的机理研究，并证实[(PN-2)­CuF]₂是与芳基硼酸酯发生转金属化反应的活性物种。