Multitopic third generation tris(pyrazolyl)methane ligands built on alkyne structural scaffolding: first preparation of mixed tris(pyrazolyl)methane/tris(pyrazolyl)borate ligands
作者:Daniel L. Reger、James R. Gardinier、Selma BakbakCurrent address: School of Ch、Radu F. Semeniuc、Uwe H. F. Bunz、Mark D. Smith
DOI:10.1039/b414770g
日期:——
A series of new multitopic ligands with rigid linear geometry are formed by joining tris(pyrazolyl)methane and tris(pyrazolyl)borate units with arenyl and alkynyl linkers using Sonogashira and related alkynyl coupling reactions. These ligands are new examples of “third generation” poly(pyrazolyl)borate and poly(pyrazolyl)methane ligands, ligands functionalized at the non-coordinating “back” positions of either the boron or central carbon atoms. The reaction of Na[OCH2C(pz)3] with propargyl bromide yields HC2CH2OCH2C(pz)3
(2) and homocoupling of this alkyne yields [-C2CH2OCH2C(pz)3]2. The reaction of Na[OCH2C(pz)3] with 3,5-(BrCH2)2C6H3I yields 3,5-[(pz)3CCH2OCH2]2C6H3I (4), which can be converted to 3,5-[(pz)3CCH2OCH2]2C6H3(C2H)
(6) by reaction with HC2SiMe3 followed by removal of the SiMe3 group. Compounds 4 and 6 can be combined to form 3,3′,5,5′-[(pz)3CCH2OCH2]4(1,1′-C6H3C2C6H3)
(7) and 6 homocoupled to form 3,5-[(pz)3CCH2OCH2]2C6H3C2-}2. Compound 6 reacts with p-I2C6H4 to produce 3,3′,5,5′-[(pz)3CCH2OCH2]4[p-(1,1′-C6H3C2)2C6H4], which can also be formed by the reaction of 4 with bis(ethynyl)benzene. The reaction of 2 with Fe[(p-IC6H4)B(pz)3]2 yields the bitopic, metalloligand Fe[(pz)3CCH2OCH2-C2-C6H4B(κ3-N,N′,N″-pz)3]2
(10) and a similar reaction with 6 yields the tetratopic metalloligand Fe[3,5-[(pz)3CCH2OCH2]2C6H3C2}C6H4B(κ3-N,N′,N″-pz)3]2. The molecular structures of 2, 4, 7, and 10·4CH2Cl2 are reported and their supramolecular structures, organized by a series of CH⋯I and CH–π interactions, are detailed.
利用 Sonogashira 和相关的炔基偶联反应,将三(吡唑基)甲烷和三(吡唑基)硼酸酯单元与壬基和炔基连接体连接起来,形成了一系列具有刚性线性几何形状的新型多位配体。这些配体是 "第三代 "聚(吡唑基)硼酸酯和聚(吡唑基)甲烷配体的新实例,这些配体在硼原子或中心碳原子的非配位 "背面 "位置进行了官能化。Na[OCH2C(pz)3] 与溴化丙炔反应生成 HC2CH2OCH2C(pz)3 (2),将该炔烃同偶联生成 [-C2CH2OCH2C(pz)3]2。Na[OCH2C(pz)3] 与 3,5-(BrCH2)2C6H3I 反应生成 3,5-[(pz)3CCH2OCH2]2C6H3I (4),通过与 HC2SiMe3 反应并去除 SiMe3 基团,可将其转化为 3,5-[(pz)3CCH2OCH2]2C6H3(C2H) (6)。化合物 4 和 6 合并可生成 3,3′,5,5′-[(pz)3CH2OCH2]4(1,1′-C6H3C2C6H3)(7),6 同偶联可生成 3,5-[(pz)3CH2OCH2]2C6H3C2-}2。化合物 6 与 p-I2C6H4 反应生成 3,3′,5,5′-[(pz)3CCH2OCH2]4[p-(1,1′-C6H3C2)2C6H4],该化合物也可由 4 与双(乙炔基)苯反应生成。2 与 Fe[(p-IC6H4)B(pz)3]2 反应可生成位金属配体 Fe[(pz)3CCH2OCH2-C2-C6H4B(κ3-N,N′、N″-pz)3]2 (10),并与 6 发生类似反应,得到四位金属配体 Fe[3,5-[(pz)3CCH2OCH2]2C6H3C2}C6H4B(κ3-N,N′,N″-pz)3]2。报告了 2、4、7 和 10-4CH2Cl2 的分子结构,并详细介绍了它们通过一系列 CH⋯I 和 CH-π 相互作用而形成的超分子结构。