10.1021/om0401004.s002
Joanne O. Yu
Joanne O.
Yu
Edmond Lam
Edmond
Lam
Julie L. Sereda
Julie L.
Sereda
Nicole C. Rampersad
Nicole C.
Rampersad
Alan J. Lough
Alan J.
Lough
C. S. Browning
C. S.
Browning
David H. Farrar
David H.
Farrar
2-Indolylphosphines, a New Class of Tunable Ligands:
Their Synthesis, Facile Derivatization, and Coordination
to Palladium(II)
American Chemical Society
2005
metal complexes
13 C
Ligand
dimeric structure
indolylphenylphosphines L
Pd
diphenyl
New Class
bi
indolyl nitrogen
indolyl NH groups
ligand
Facile Derivatization
31 P NMR spectroscopy
transition metal
F 5 Bz
1 H
mass spectrometry
novel polydentate
CH 2 C 6 F 5
1 equiv
2005-01-03 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/2_Indolylphosphines_a_New_Class_of_Tunable_Ligands_Their_Synthesis_Facile_Derivatization_and_Coordination_to_Palladium_II_/3306103
The generation of new metal complexes with potentially interesting properties provides
the motivation for designing novel polydentate bridging ligands. Herein we report the
syntheses of tertiary indolylphenylphosphines <b>L</b>, where <b>L</b> = diphenyl(3-methyl-2-indolyl)phosphine (P(C<sub>6</sub>H<sub>5</sub>)<sub>2</sub>(C<sub>9</sub>H<sub>8</sub>N), <b>1</b>), phenylbis(3-methyl-2-indolyl)phosphine (P(C<sub>6</sub>H<sub>5</sub>)(C<sub>9</sub>H<sub>8</sub>N)<sub>2</sub>,
<b>2</b>), and bis(1<i>H</i>-3-indolyl)methane-(2,12)-phenylphosphine (P(C<sub>6</sub>H<sub>5</sub>)(C<sub>17</sub>H<sub>12</sub>N<sub>2</sub>), <b>3</b>). Ligands <b>1</b>−<b>3</b>
were functionalized at the indolyl nitrogen with a variety of both electron-withdrawing and
electron-donating groups. The solid-state structures of <b>1</b>, <b>2</b>, and N-functionalized indolylphosphines diphenyl(3-methyl-1-benzyl-2-indolyl)phosphine (P(C<sub>6</sub>H<sub>5</sub>)<sub>2</sub>(C<sub>9</sub>H<sub>7</sub>N(CH<sub>2</sub>C<sub>6</sub>H<sub>5</sub>)), <b><i>N</i></b><b>-Bz-1</b>) and bis[1-(CH<sub>2</sub>C<sub>6</sub>F<sub>5</sub>)-3-indolyl]methane-(2,12)-phenylphosphine (P(C<sub>6</sub>H<sub>5</sub>)(C<sub>17</sub>H<sub>10</sub>N<sub>2</sub>[CH<sub>2</sub>C<sub>6</sub>F<sub>5</sub>]<sub>2</sub>),
<b>(</b><b><i>N</i></b><b>-F</b><b><sub>5</sub></b><b>Bz)</b><b><sub>2</sub></b><b>-3</b>), are reported. The reaction of ligands <b>1</b>−<b>3</b> with 1 equiv of Pd(COD)Cl<sub>2</sub> led to
the formation of Pd(II) complexes of the type [Pd(<b>L</b>)Cl(μ-Cl)]<sub>2</sub> (<b>4</b>, <b>L </b>= <b>1</b>; <b>5, L </b>= <b>2</b>; <b>6, L </b>= <b>3</b>).
The products were characterized by <sup>1</sup>H, <sup>13</sup>C, and <sup>31</sup>P NMR spectroscopy, mass spectrometry,
and elemental analysis. X-ray crystallography established the dimeric structure of the
products and confirmed the ability of the ligands to serve, in the absence of base, as
monodentate P-donors in reaction with a transition metal. The indolyl NH groups of the
complexes <b>4</b>−<b>6</b> demonstrate a marked propensity for hydrogen bonding in the solid state.