10.1021/om049897p.s007
Sarah B. Cortright
Sarah B.
Cortright
John C. Huffman
John C.
Huffman
Ryan A. Yoder
Ryan A.
Yoder
Joseph N. Coalter
Joseph N.
Coalter
Jeffrey N. Johnston
Jeffrey N.
Johnston
IAN Amines: Chiral <i>C</i><sub>2</sub>-Symmetric Zirconium(IV)
Complexes from Readily Modified Axially Chiral
<i>C</i><sub>1</sub>-Symmetric β-Diketimines
American Chemical Society
2004
metallocene complexes
configurational integrity
derivative
t Bu
pyridyl ligands
Symmetric
ethylene polymerization
enantioselective addition
metal coordination
transfer asymmetry
Modified Axially Chiral C 1
homochiral ligands
ci
mino N aphthalene components
i Pr
NMe 2
topographical similarity
C 2
steric hindrance
IAN amines
2 Ph
2004-05-10 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/IAN_Amines_Chiral_i_C_i_sub_2_sub_Symmetric_Zirconium_IV_Complexes_from_Readily_Modified_Axially_Chiral_i_C_i_sub_1_sub_Symmetric_Diketimines/3340222
A general synthesis of β-diketimines derived from <i>I</i>soquinoline and <i>A</i>mino<i>N</i>aphthalene
components (IAN amines) is reported. Beginning from inexpensive 2-naphthol and isoquinoline, the sequence of reactions leading to R-IAN amines is convergent, short, and high-yielding. Several new derivatives are reported (e.g., R = Bn, <i><sup>i</sup></i><sup></sup>Pr, <i><sup>t</sup></i><sup></sup>Bu, Ph, 2,6-Me<sub>2</sub>Ph, 2,6-<i><sup>i</sup></i><sup></sup>Pr<sub>2</sub>Ph, 2-Np). All of these were complexed to zirconium(IV) by transamination with
Zr(NMe<sub>2</sub>)<sub>4</sub>, and in all cases 1:1 R-IAN:Zr complexes immediately formed at 25 °C. Except in
cases of severe steric hindrance (<i><sup>i</sup></i><sup></sup>Pr-IAN and 2,6-Me<sub>2</sub>Ph), the corresponding 2:1 IAN:Zr
complexes formed at temperatures ranging from 25 to 100 °C in toluene. A feature conserved
among all 2:1 IAN:Zr complexes was a remarkable degree of diastereoselectivity favoring a
<i>C</i><sub>2</sub>-symmetric bis(β-diketiminate) isomer bearing <i>cis</i>-NMe<sub>2</sub> and <i>cis</i>-pyridyl ligands. Although
all complexations were performed from <i>rac</i>-IAN, the resulting complexes are composed solely
of homochiral ligands. The configurational integrity of Me-IAN and its ability to transfer
asymmetry upon metal coordination was demonstrated in the catalyzed enantioselective
addition of diethylzinc to benzaldehyde. Given the topographical similarity between these
and metallocene complexes, several derivatives were preliminarily evaluated in ethylene
polymerization.