Stabilized Gallylene in a Pincer‐Type Ligand: Synthesis, Structure, and Reactivity of PGa^IP‐Ir Complexes

Abstract

Iridium complexes having ap incer-type gallylene ligand were successfully synthesized utilizing bis(phosphino)terpyridine as an efficient scaffold for the IrÀGa I bond. The stabilization of the gallylene moiety by the pincer-type structure enabled various reactions at Ir with keeping the gallylene ligand intact, leading to unique structures and reactivities of PGa I P À Ir complexes.

The Pincer Platform Beyond Classical Coordination Patterns

“…In this case the [ECl 4 ] – counterion does not interact with the metal center and a chloride substituent migrates from the gallium to the iridium center upon coordination. [ 134 ] Formally, the formed complex 49 may be described as square pyramidal iridium(I) complex with a Lewis acidic cationic gallium(III)‐based ligand or as iridium(III) complex with a gallylene‐based donor group. Strong evidence for the latter interpretation is provided by the reaction with a chloride ion source such as Bu 4 NCl, which leads to the coordination of a chloride ligand to the iridium center rather than to the gallium atom.…”

Stabilized Gallylene in a Pincer‐Type Ligand: Synthesis, Structure, and Reactivity of PGaIP‐Ir Complexes

“…ORTEP drawings of a) 3 and b) 4 at the 50 %p robability level. [24] [GaCl 4 ] À and hydrogen atoms are omitted for clarity.S elected bond lengths []and angles [8 8]: 3:Ir-Cl1 2.310(1), Ir-Cl2 2.370(1), Ga-Cl2 2.725(1), Ir-Ga 2.3895(6), Ga-Cl3 2.226(1), Ir-P1 2.320(1), Ir-P2 2.327(1);P 1-Ir-P2 176.04(4), Cl1-Ir-Cl2 170.13(4). 4:I r-Cl1 2.3690-(9), Ir-Cl2 2.5459(9), Ir-Cl3 2.3924(9), Ga-Cl3 2.8906(8), Ga-Cl4 2.2628(9), Ir-Ga 2.3970 (7), Ir-P1 2.3426(9), Ir-P2 2.3350(9); P1-Ir-P2 172.…”

“…ORTEP drawing of 6 at the 50 %probability level [24]. Hydrogen atoms are omitted for clarity.S elected bond lengths []a nd angles [8 8]: Ir-Cl1 2.390(2), Ir-Ga1 2.377(1), Ir-Ga2 2.456(1), Ga1-Ga23 .010-(1), Ga1-Cl2 2.258(2), Ir-P1 2.310(2), Ir-P2 2.316(2);P 1-Ir-P2 168.50-(8), Cl1-Ir-Ga1 140.26(6), Cl1-Ir-Ga2 142.71(6), Ga1-Ir-Ga2 77.02(3).…”

“…ORTEP drawings of a) 7 and b) 8 at the 50 %probability level [24]. Hydrogen atoms except SiH 2 and IrH 2 are omitted for clarity.…”

Rhodium‐Catalyzed C−H Activation Enabled by an Indium Metalloligand

“…[1c,4,5] The groups of Lu and Tauchert and our group have developed N,P-multidentate ligands as suitable supports for M À Zbonds (Z = group 13 metals,Li, Cu, Zn), in which the Z-type ligands substantially affect the reactivity of group 10 metals for hydrogenation and hydrosilylation reactions. [6][7][8] However, previous reports have mostly focused on phosphine-based supports for MÀZb onds to give metal complexes with PZPpincer-type or ZP 3 -tetradentate tripodal ligands,a nd the reactions they can catalyze are rather limited to activation of alkynes and E À Hb onds (E = H, Si). [9] Therefore,t he development of novel M À Zc omplexes that enable new modes of catalysis control by Z-type ligands is necessary in order to extend their usage in synthetic chemistry.…”