Enantioselective Synthesis of Alcohols and Amines by Iridium‐Catalyzed Hydrogenation, Transfer Hydrogenation, and Related Processes

Abstract

The preparation of chiral alcohols and amines by using iridium catalysis is reviewed. The methods presented include the reduction of ketones or imines by using hydrogen (hydrogenations), isopropanol, formic acid, or formate (transfer hydrogenations). Also dynamic and oxidative kinetic resolutions leading to chiral alcohols and amines are included. Selected literature reports from early contributions to December 2012 are discussed.

Nickel N-heterocyclic carbene complexes and their utility in homogeneous catalysis

“…The transition metal mediated reduction of ketones in a protic solvent by transfer hydrogenation provides an easy access to chiral alcohols [293] (Scheme 41). …”

General, Simple, and Chemoselective Catalysts for the Isomerization of Allylic Alcohols: The Importance of the Halide Ligand

“…However, under our reaction conditions, reduction of the product aldehydes yielding saturated alcohols was not detected. [15] The compatibility with functional groups in complex molecules was demonstrated with morphine (5) and codeine (6). [16 ] Due to solubility, H2O was replaced by i PrOH (SI), which resulted in excellent yields of hydromorphone (7) and hydrocodone (8) Mechanistic investigations were undertaken to understand the lack of reactivity of halogen-free complexes.…”

Hydrogenation of CO2 to formic acid with iridiumIII(bisMETAMORPhos)(hydride): the role of a dormant fac-IrIII(trihydride) and an active trans-IrIII(dihydride) species

“…This complex is thus likely not a derivative of 1, nor does it match previously described deactivation products. 18 Catalytic hydrogenation of CO 2 to formate with an Ir III (METAMORPhos) complex in the presence of DBU requires a trans-dihydride for catalytic turnover, with an off-cycle trihydride as dormant species. …”