Nickel-Catalyzed Cross-Coupling of Phenols and Arylboronic Acids Through an In Situ Phenol Activation Mediated by PyBroP
作者:Guo-Jun Chen、Jie Huang、Lian-Xun Gao、Fu-She Han
DOI:10.1002/chem.201003403
日期:2011.3.28
towards a wide range of both phenols and boronic acids, including activated, nonactivated, deactivated, and heteroaromatic coupling partners. In addition, various functional groups, such as ether, amino, cyano, ester, and ketone groups, are compatible with this transformation. Notably, arylboronic acids containing an unprotected NH2 group and 2‐heterocyclic boronic acids, which are generally problematic
提出了一种通过PyBroP介导的原位苯酚活化,使Suzuki-Miyaura苯酚和芳基硼酸交叉偶联的新方法。通过使用经济高效,显着稳定的[NiCl 2(dppp)](dppp = 1,3-双(二苯基膦基)丙烷)作为催化剂,仅以5 mol%的负载量进行反应,并且无需添加额外的催化剂即可有效地进行反应配体。该方法对多种酚和硼酸都具有广泛的适用性和高效率,包括活化,非活化,失活和杂芳族偶联伙伴。另外,各种官能团,例如醚,氨基,氰基,酯和酮基团与该转化相容。值得注意的是,含有未保护的NH 2的芳基硼酸尽管在空间受限的底物上获得了中等收率,但在常规条件下偶合时通常存在问题的基团和2-杂环硼酸也是可行的底物。因此,原位交叉偶联方法与廉价,稳定的镍催化剂的使用为从易得的酚类化合物组装结构多样的联芳基和杂联芳基提供了一种快速有效的途径。