chemistry of the ruthenium PNP-type complexes cannot be simply extrapolated to
the iron systems. This is already reflected by how the iron-based (pre)catalysts are
made (Scheme 17). First of all, iron analogs of the ruthenium precursors RuHCl(CO)
(PPh 3 ) 3 and Ru(COD)(2-methylallyl) 2 do not exist. While the catalysis community
enjoys the use of Ru-MACHO and Ru-MACHO-BH, both of which are
Scheme 17 Synthetic routes to iron-based hydrogenation (pre)catalysts
286
D. A. Ekanayake and H. Guan
the iron systems. This is already reflected by how the iron-based (pre)catalysts are
made (Scheme 17). First of all, iron analogs of the ruthenium precursors RuHCl(CO)
(PPh 3 ) 3 and Ru(COD)(2-methylallyl) 2 do not exist. While the catalysis community
enjoys the use of Ru-MACHO and Ru-MACHO-BH, both of which are
Scheme 17 Synthetic routes to iron-based hydrogenation (pre)catalysts
286
D. A. Ekanayake and H. Guan