Diboron-Promoted Reduction of Ni(II) Salts: Precatalyst Activation Studies Relevant to Ni-Catalyzed Borylation Reactions
作者:Matthew V. Joannou、Amy A. Sarjeant、Steven R. Wisniewski
DOI:10.1021/acs.organomet.1c00325
日期:2021.8.9
coordination complexes were also isolated when a phosphine, phosphite, and/or diene ligand was present, all starting from NiCl2·6H2O, including the following: Ni[P(OPh)3]4 (74% yield), Ni[P(OiPr)3]4 (54% yield), Ni(PPh3)4 (75% yield), (dppp)2Ni + Ni(1,5-cod)2 (dppp = 1,3-bis(diphenylphosphine)propane) (91% yield), Ni(1,5-cod)2 (1,5-cod = 1,5-cyclooctadiene) (69% yield), and (dppf)Ni(1,5-cod) (dppf = 1,1′-bi
报道了在与 Ni 催化的硼化反应相关的条件下镍 (II) 盐的活化和还原。NiCl 2 ·6H 2 O 的甲醇溶液与 >2 当量的 ( i Pr) 2 NEt 反应后转化为聚合 Ni(OMe) 2,通过红外光谱、磁化率测量进行表征,并通过独立合成 NaOMe 进行验证。当二硼试剂如双(新戊基乙醇酸)二硼 (B 2 (npg) 2 ) 暴露于 Ni(II) 盐和 ( i Pr) 2 的甲醇溶液时NEt,镍金属随着氢气的释放而沉积。还观察到镍金属的产率与 B 2 (npg) 2相对于 [Ni] 的当量之间的直接关系,在 8 当量时达到 >99% 的产率。当存在膦、亚磷酸酯和/或二烯配体时,Ni(0) 配位络合物也被分离出来,所有这些都从 NiCl 2 ·6H 2 O 开始,包括以下物质:Ni[P(OPh) 3 ] 4(74% 的产率) ),镍[P(O我PR)3 ] 4(54%收率),N我(PPH