钯催化苯基硼酸酯的合成

Palladium-catalyzed Synthesis of Phenylboronate

摘要:

以三(二亚苄基丙酮)二钯(Pd2dba3)为催化剂，2-双环己基膦-2',4',6'-三异丙基联苯(Xphos)为配体，采用联硼酸频哪醇酯[B2(pin)2]与对叔丁基氯苯(4-tert-butyl-1-chlorobenzene)反应合成对叔丁基苯基硼酸酯。通过研究Pd催化剂与配体的用量及比例、硼试剂的用量、碱的种类、不同的反应溶剂及温度对反应收率的影响，确定了苯基硼酸酯合成的最佳条件为： n(对叔丁基氯苯) : n(Pd2dba3) : n(Xphos) ： n[B2(pin)2] : n(KOAc) = 1: 0.01 : 0.04 : 2 : 3，以乙醇(EtOH)为溶剂于60℃反应1 h，收率达98%。

Abstract:

In the preparation of pinacol(4-tert-butylbenzene)boronate by Pd-catalyzed borylation of 4-tert-buty-1-chlorobenzene,Pd2dba3 was used as catalyst,Xphos as ligand and B2(pin)2 as boron source.The effects of the quantity of boron source,different kinds of bases, ratio of the catalyst to the ligand, solvents and temperatures on the yield of the product were studied. The optimum conditions were determined as follows: n(4-tert-butyl-1-chlorobenzene) : n(Pd2dba3) : n(Xphos) ： n[B2(pin)2] : n(KOAc) = 1 : 0.01 : 0.04 : 2 : 3 in EtOH at 60℃ for 1 h.The yield can reach 98%.