Highly Robust Efficient Catalyst For Selective Dehydrogenation Of Neat Glycerol To Lactic Acid

摘要

A catalyst system includes a complex having formula I which advantageously has a sterically protecting N-heterocyclic carbene (NHC) carbene-pyridine ligand to handle harsh reactions conditions than many prior art catalysts:; ;wherein M is a transition metal; o is 0, 1, 2, 3, or 4; R₁ is a C_1-6 alkyl, a C_6-18 aryl, or an optionally substituted C_5-18 heteroaryl. In a refinement, R₁ is methyl, ethyl, butyl, n-propyl, isopropyl, n-butyl, sec-butyl, or t-butyl; R₂, R₃, R₃′ are independently an optionally substituted C_1-6 alkyl, halo (e.g., Cl, F, Br, etc), NO₂, an optionally substituted C_6-18 aryl, or an optionally substituted C_5-18 heteroaryl; R₄, R₄′ are independently an optionally substituted C_1-6 alkyl, halo, NO₂, an optionally substituted C_6-18 aryl, or an optionally substituted C_5-18 heteroaryl; and X⁻ is a negatively charge counter ion and L₁, L₂ are each independently a neutral ligand.