*2.3.1 Cp\*IrCl2(NHC) in hydrogen transfer initiated dehydration (HTID)*

A recyclable Cp\*IrCl2(NHC) (Cp\* = pentamethylcyclopentadienyl) complex in ionic liquid could covert glycerol into 1,3-propanediol and subsequently to propionaldehyde by hydrogen transfer initiated dehydration (HTID) in excellent yields in the presence of air (**Figure 11**) [34, 35].

**Figure 10.** *Oxidation of sugar alcohols to lactic acid.*

**Figure 11.** *Cp\*IrCl2(NHC) in hydrogen transfer initiated dehydration (HTID).*
