Chu Xiaodan, Zhang Shaowei, Wang Zhuo, Li Tongyu, Zhu Bolin
Tianjin Key Laboratory of Structure and Performance for Functional Molecules, Key Laboratory of Inorganic-Organic Hybrid Functional Material Chemistry, Ministry of Education, College of Chemistry, Tianjin Normal University Tianjin 300387 People's Republic of China
RSC Adv. 2018 Feb 14;8(13):7164-7172. doi: 10.1039/c7ra13547e. eCollection 2018 Feb 9.
Reactions of 2-benzoylpyridine or 2-benzylpyridine with [CpMCl] (M = Ir, Rh) have been carried out in the presence of NaOAc in refluxing methanol, which form the corresponding six-membered cyclometalated products (1-3) except for the reaction of 2-benzylpyridine with [CpRhCl]. Insertion reactions of two six-membered cyclometalated pyridine iridium complexes (1 and 2) with terminal or internal aromatic alkynes were studied. Terminal alkynes -XCHC[triple bond, length as m-dash]CH (X = H, MeO, and F) with 1 give the corresponding five- and seven-membered doubly cycloiridated complexes 4a-c, internal alkynes -XCHC[triple bond, length as m-dash]CCHX- (X = H, MeO, and Br) form the similar five- and seven-membered doubly cycloiridated complexes (5a,b) and/or di-insertion products (6a,c), whereas the acyl alkyne PhC[triple bond, length as m-dash]CCOPh affords the novel spiro-metalated complex 7. For complex 2, internal alkynes -XCHC[triple bond, length as m-dash]CCHX- (X = H, MeO, and Br) form similar five- and seven-membered doubly cycloiridated complexes (8a-c). However, in the case of PhC[triple bond, length as m-dash]CCOPh, the reaction gives the novel four-membered cyclometalated complex 9. These results suggest that the products formed by alkyne insertion reactions of the six-membered cycloiridated pyridine complexes are very diverse. Plausible pathways for the formation of these novel insertion products were proposed. Molecular structures of seven cyclometalated complexes were determined by X-ray diffraction.
2-苯甲酰基吡啶或2-苄基吡啶与[CpMCl]（M = Ir，Rh）在回流甲醇中于醋酸钠存在下进行反应，除了2-苄基吡啶与[CpRhCl]的反应外，均形成相应的六元环金属化产物（1 - 3）。研究了两种六元环金属化吡啶铱配合物（1和2）与末端或内芳基炔烃的插入反应。末端炔烃-XCHC≡CH（X = H、MeO和F）与1反应生成相应的五元及七元双环铱配合物4a - c，内炔烃-XCHC≡CCHX-（X = H、MeO和Br）形成类似的五元及七元双环铱配合物（5a，b）和/或双插入产物（6a，c），而酰基炔烃PhC≡CCOPh则生成新型螺金属化配合物7。对于配合物2，内炔烃-XCHC≡CCHX-（X = H、MeO和Br）形成类似的五元及七元双环铱配合物（8a - c）。然而，在PhC≡CCOPh的情况下，反应生成新型四元环金属化配合物9。这些结果表明，六元环铱吡啶配合物的炔烃插入反应形成的产物非常多样。提出了这些新型插入产物形成的可能途径。通过X射线衍射确定了七种环金属化配合物的分子结构。
