ordinary hydrogenation of aromatic rings is going to yield racemic products but stereoselective hydrogenation is here achieved with a bespoke chiral organoriridium catalyst. most of the synthetic procedure describes how to make that catalyst starting from (1S,2S)-1,2-diphenylethylenediamine. again, a vicinal diamine serves as a building block for a chiral ligand stuck on a transition metal
pentamethylcyclopentadienyliridium(III) dichloride dimer serves as the iridium source for the synthesis
and once you get the catalyst made, it's used to hydrogenate quinaldine (2-methylquinoline) to (S)-2-methyl-1,2,3,4-tetrahydroquinoline, in 94% enantiomeric excess, by hydrogenation at 50 atm pressure of hydrogen gas in a solvent of methanol spiked with trifluoroacetic acid, probably to insure protonation of the quinaldine (I suspect that without it you might get the 1,4-dihydroquinoline instead)
neat, I guess? nothing I can see wanting to do any time soon. who has iridium lying around