MACHO catalyst

In homogeneous catalysis, MACHO catalysts are metal complexes containing MACHO ligands, which are of the type HN(CH2CH2PR2)2, where R is typically phenyl or isopropyl.

Complexes with ruthenium(II) and iridium(III) have received much attention for their ability to hydrogenate polar bonds such as those in esters and even carbon dioxide.

[1] The catalysts appear to operate via intermediates where the amine proton and the hydride ligand both interact with the substrate.

[2][3] The Ru-MACHO catalyst have been commercialized for the synthesis of 1,2-propanediol from bio-derived methyl lactate.

[4]