Heteroleptic Ni(II) Complexes Bearing a Bulky Yet Flexible IBiox-6 Ligand: Improved Selectivity in Cross-Electrophile Coupling of Benzyl Chlorides with Aryl Chlorides/Fluorides
作者:Zheng-Wang Shen、Die-Die Meng、Sajid Imran、Chun-Hui Yan、Hong-Mei Sun
DOI:10.1021/acs.organomet.0c00515
日期:2020.10.12
Ni(PPh3)2Br2 to give the respective heteroleptic Ni(II) complexes Ni(IBiox-6)[P(OEt)3]Br2 (1) and Ni(IBiox-6)(PPh3)Br2 (2) in yields of 60% and 71%. Their crystal structures were characterized to reveal a rare cis disposition of the IBiox-6 ligand to the phosphite ligand in 1, while 2 possessed the more common trans configuration. Both complexes catalyzed the cross-electrophile coupling of benzyl chlorides
名为IBiox-6的双恶唑啉衍生的NHC与Ni [P(OEt)3 ] 2 Br 2和Ni(PPh 3)2 Br 2平稳反应,分别得到杂配的Ni(II)配合物Ni(IBiox-6)[ P(OEt)3 ] Br 2(1)和Ni(IBiox-6)(PPh 3)Br 2(2)的产率分别为60%和71%。它们的晶体结构进行了表征揭示一种罕见的顺式的IBiox-6配体在亚磷酸盐配体的布置1,而2所具有的较常见的反式组态。两种配合物均通过“真正的一锅法”在50°C的Mg车削条件下催化了苄基氯与芳基氯和氟化物的亲电子交联偶联,其特点是不需要温度变化或分批添加任何偶联伴侣。特别地,配合物1在催化活性和选择性之间显示出更好的平衡。研究了由1和Mg车削催化的程序范围,为合成具有高位阻和各种官能团的二芳基甲烷提供了一种高度选择性,简单和实用的方法,包括具有不对称结构的低聚二芳基甲烷。