Scholarlink

Abstract <p>The reaction of equimolar amounts of tris((2-<i>N</i>-piperidinomethyl)phenyl)methanol (2‑C<sub>5</sub>H<sub>10</sub>NCH<sub>2</sub>-<i>o-</i>C<sub>6</sub>H<sub>4</sub>)<sub>3</sub>COH and [(Me<sub>3</sub>Si)<sub>2</sub>N]<sub>2</sub>Ca(THF)<sub>2</sub> (toluene, 23<sup>○</sup>C) resulted in the synthesis of mixed-ligand calcium alkoxide-amide complex [(2-C<sub>5</sub>H<sub>10</sub>NCH<sub>2</sub>C<sub>6</sub>H<sub>4</sub>)<sub>3</sub>CO]CaN(SiMe<sub>3</sub>)<sub>2</sub> (<b>I</b>) in 70% yield. According to X-ray diffraction data, the monoanionic alkoxide ligand in <b>I</b> is coordinated to the metal in the κ<sup>3</sup>-O,N,N-mode. Complex <b>I</b> catalyzes the addition of PhSiH<sub>3</sub> to annulated N-containing heterocycles: quinoline, 4-methylquinoline, 6-methylquinoline, and isoquinoline. The reactions are chemo- and regioselective and proceed over periods of 24 to 120 h. The reaction of <b>I</b> with PhSiH<sub>3</sub> (molar ratio of 1 : 2) gives the bis(alkoxide) complex [κ<sup>2</sup>-O,N-(2-C<sub>5</sub>H<sub>10</sub>NCH<sub>2</sub>C<sub>6</sub>H<sub>4</sub>)<sub>3</sub>CO]<sub>2</sub>Ca (<b>II</b>) and CaH<sub>2</sub> as a result of symmetrization of the intermediate calcium alkoxy hydride. In the crystalline state, complex <b>II</b> has a non-linear structure, with the OCa(1)O angle being 112.65(4)° and only one of the piperidine moieties in each ligand being involved in the coordination to the metal ion. The molecular structure of complexes <b>I</b> and <b>II</b> was determined using X-ray diffraction (CCDC nos. 2443979 (<b>I</b>), 2443980 (<b>II</b>)).</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Calcium Complexes with the Bulky Tris((2-N-piperidinomethyl)phenyl)methoxide Ligand. Synthesis and Catalytic Activity in the Dearomatization of N-Heterocycles

  • 期刊论文

  • 发表日期：

    2025年6月1日

查看全文
  • A. N. Selikhov,
  • Yu. V. Nelyubina,
  • A. A. Trifonov

摘要

Abstract

The reaction of equimolar amounts of tris((2-N-piperidinomethyl)phenyl)methanol (2‑C5H10NCH2-o-C6H4)3COH and [(Me3Si)2N]2Ca(THF)2 (toluene, 23○C) resulted in the synthesis of mixed-ligand calcium alkoxide-amide complex [(2-C5H10NCH2C6H4)3CO]CaN(SiMe3)2 (I) in 70% yield. According to X-ray diffraction data, the monoanionic alkoxide ligand in I is coordinated to the metal in the κ3-O,N,N-mode. Complex I catalyzes the addition of PhSiH3 to annulated N-containing heterocycles: quinoline, 4-methylquinoline, 6-methylquinoline, and isoquinoline. The reactions are chemo- and regioselective and proceed over periods of 24 to 120 h. The reaction of I with PhSiH3 (molar ratio of 1 : 2) gives the bis(alkoxide) complex [κ2-O,N-(2-C5H10NCH2C6H4)3CO]2Ca (II) and CaH2 as a result of symmetrization of the intermediate calcium alkoxy hydride. In the crystalline state, complex II has a non-linear structure, with the OCa(1)O angle being 112.65(4)° and only one of the piperidine moieties in each ligand being involved in the coordination to the metal ion. The molecular structure of complexes I and II was determined using X-ray diffraction (CCDC nos. 2443979 (I), 2443980 (II)).