2 research outputs found
Synthesis of Heteroaryl Compounds through Cross-Coupling Reaction of Aryl Bromides or Benzyl Halides with Thienyl and Pyridyl Aluminum Reagents
No full textAn
efficient method for synthesis of useful biaryl building blocks
containing 2-thienyl, 3-thienyl, 2-pyridyl, and 3-pyridyl moieties
was provided through cross-coupling reactions of aryl bromides or
benzyl halides with heteroaryl aluminum reagents in the presence of
PdÂ(OAc)<sub>2</sub> and (<i>o</i>-tolyl)<sub>3</sub>P. The
coupling reaction also worked efficiently with heteroaryl bromides
affording series of heterobiaryl compounds. The reaction of phenylbromide
with in situ prepared 3-pyridyl aluminum was demonstrated to afford
the product <b>8a</b> in high yield. Additionally, the catalytic
system was also suited well for the coupling reaction of benzyl halides
with pyridyl aluminum reagents to afford series of pyridyl-arylmethane
Controlled Synthesis of Racemic Indenyl Rare-Earth Metal Complexes via the Cooperation between the Intramolecular Coordination of Donor Atoms and a Bridge
No full textThe
reactions of Me<sub>2</sub>SiÂ(C<sub>9</sub>H<sub>6</sub>CH<sub>2</sub>CH<sub>2</sub>-DG)<sub>2</sub> (DG = NMe<sub>2</sub> (<b>1</b>), CH<sub>2</sub>NMe<sub>2</sub> (<b>2</b>), OMe (<b>3</b>), and NÂ(CH<sub>2</sub>CH<sub>2</sub>)<sub>2</sub>O (<b>4</b>)) with [(Me<sub>3</sub>Si)<sub>2</sub>N]<sub>3</sub>REÂ(μ-Cl)ÂLiÂ(THF)<sub>3</sub> in toluene afforded a series of racemic divalent rare-earth
metal complexes: {η<sup>5</sup>:η<sup>1</sup>:η<sup>5</sup>:η<sup>1</sup>-Me<sub>2</sub>SiÂ(C<sub>9</sub>H<sub>5</sub>CH<sub>2</sub>CH<sub>2</sub>-DG)<sub>2</sub>}ÂRE (DG = NMe<sub>2</sub>, RE = Yb (<b>6</b>) and Eu (<b>7</b>); DG = CH<sub>2</sub>NMe<sub>2</sub>, RE = Yb (<b>8</b>), Eu (<b>9</b>), and
Sm (<b>10</b>); DG = OMe, RE = Yb (<b>11</b>) and Eu (<b>12</b>); DG = NÂ(CH<sub>2</sub>CH<sub>2</sub>)<sub>2</sub>O, RE
= Yb (<b>13</b>) and Eu (<b>14</b>)). Similarly, the racemic
divalent rare-earth metal complexes {η<sup>5</sup>:η<sup>1</sup>:η<sup>5</sup>:η<sup>1</sup>-Me<sub>2</sub>SiÂ(C<sub>9</sub>H<sub>5</sub>CH<sub>2</sub>CH<sub>2</sub>CH<sub>2</sub>NMe<sub>2</sub>)Â(C<sub>9</sub>H<sub>5</sub>CH<sub>2</sub>CH<sub>2</sub>OMe)}ÂRE
(RE = Yb (<b>15</b>) and Eu (<b>16</b>)) were also obtained.
The reaction of Me<sub>2</sub>SiÂ(C<sub>9</sub>H<sub>5</sub>CH<sub>2</sub>CH<sub>2</sub>OMe)<sub>2</sub>Li<sub>2</sub> with NdCl<sub>3</sub> gave a racemic dimeric neodymium chloride {η<sup>5</sup>:η<sup>1</sup>:η<sup>5</sup>-Me<sub>2</sub>SiÂ(C<sub>9</sub>H<sub>5</sub>CH<sub>2</sub>CH<sub>2</sub>OMe)<sub>2</sub>NdCl}<sub>2</sub> (<b>17</b>), whereas the reaction of Me<sub>2</sub>SiÂ(C<sub>9</sub>H<sub>5</sub>CH<sub>2</sub>CH<sub>2</sub>NMe<sub>2</sub>)<sub>2</sub>Li<sub>2</sub> with SmCl<sub>3</sub> afforded
a racemic dinuclear samarium chloride bridged by lithium chloride
{η<sup>5</sup>:η<sup>1</sup>:η<sup>5</sup>:η<sup>1</sup>-Me<sub>2</sub>SiÂ(C<sub>9</sub>H<sub>5</sub>CH<sub>2</sub>CH<sub>2</sub>NMe<sub>2</sub>)<sub>2</sub>SmCl}<sub>2</sub>(μ-LiCl)
(<b>18</b>). Further reaction of complex <b>18</b> with
LiCH<sub>2</sub>SiMe<sub>3</sub> provided an unexpected rare-earth
metal alkyl complex {η<sup>5</sup>:η<sup>1</sup>:η<sup>5</sup>:η<sup>1</sup>:σ-Me<sub>2</sub>SiÂ(C<sub>9</sub>H<sub>5</sub>CH<sub>2</sub>CH<sub>2</sub>NMe<sub>2</sub>)Â[(C<sub>9</sub>H<sub>5</sub>CH<sub>2</sub>CH<sub>2</sub>NÂ(CH<sub>2</sub>)ÂMe]}ÂSm
(<b>19</b>) through the activation of an sp<sup>3</sup> C–H
bond α-adjacent to the nitrogen atom. Complexes <b>19</b> and {η<sup>5</sup>:η<sup>1</sup>:η<sup>5</sup>:η<sup>1</sup>:σ-Me<sub>2</sub>SiÂ(C<sub>9</sub>H<sub>5</sub>CH<sub>2</sub>CH<sub>2</sub>NMe<sub>2</sub>)Â[(C<sub>9</sub>H<sub>5</sub>CH<sub>2</sub>CH<sub>2</sub>NÂ(CH<sub>2</sub>)ÂMe]}Y (<b>20</b>) were also obtained by one-pot reactions of Me<sub>2</sub>SiÂ(C<sub>9</sub>H<sub>5</sub>CH<sub>2</sub>CH<sub>2</sub>NMe<sub>2</sub>)<sub>2</sub>Li<sub>2</sub> with RECl<sub>3</sub> followed
by treatment with LiCH<sub>2</sub>SiMe<sub>3</sub>. All compounds
were fully characterized by spectroscopic methods and elemental analysis.
Complexes <b>6</b>–<b>10</b> and <b>14</b>–<b>20</b> were further characterized by single-crystal
X-ray diffraction analysis. All of the prepared rare-earth metal complexes
were racemic, suggesting that racemic organo rare-earth metal complexes
could be controllably synthesized by the cooperation between a bridge
and the intramolecular coordination of donor atoms
