Synthesis and reactivities of Cp*Ir amide and hydride complexes bearing C-N chelate ligands

Arita, S; Koike, T; Kayaki, Y; Ikariya, T

HERO ID

4937143

Reference Type

Journal Article

Year

2008

HERO ID 4937143
In Press No
Year 2008
Title Synthesis and reactivities of Cp*Ir amide and hydride complexes bearing C-N chelate ligands
Authors Arita, S; Koike, T; Kayaki, Y; Ikariya, T
Journal Organometallics
Volume 27
Issue 12
Page Numbers 2795-2802
Abstract A series of 16-electron Cp*Ir amide complexes with C-N chelating ligands, Cp*Ir[kappa(2)(NC)-(NHCR(2)-2-C(6)H(4))] (2a: R = C(6)H(5), 2b: R = CH(3)) and the chiral version, Cp*Ir[kappa(2)(N,C)-(R)-{NHCH(CH(3))-2-C(10)H(6)}] (2e), were obtained in good to excellent yields from reactions of 18-electron iridium amine complexes, Cp*IrCl[kappa(2)(N,C)-(NH(2)CR(2)-2-C(6)H(4))] (1a: R = C(6)H(5), 1b: R = CH(3)) and Cp*IrCl[kappa(2)(N,C)-(R)-{NH(2)CH(CH(3))-2-C(10)H(6)}] (le), with a base. The amido complexes 2 readily reacted with 2-propanol to convert into hydrido(amine) complexes 3 in almost quantitative yields. The chiral amido complex has proven to serve as an efficient catalyst for asymmetric transfer hydrogenation of acetophenone with 2-propanol, giving 1-phenylethanol with a moderate ee. The Bronsted basicity on the metal-NH moiety in the amido complexes was evaluated by deprotonation of acetic acid, dimethyl malonate, and acetone, leading to the corresponding acetato(amine) complex 4 and alkyl(amine) complexes 5 and 6, respectively, indicating that the amido-Ir complexes bearing the C-N chelate have more basic properties than those with N-sulfonylated diamine ligands.
Doi 10.1021/om800124f
Wosid WOS:000256643600018
Is Certified Translation No
Dupe Override No
Is Public Yes