2,2,2-Trifluoroethanol → Sitagliptin

Participants

Reaction Conditions

Reaction Steps

Into a flask were charged bis(norbornadiene)rhodium(I) tetrafluoroborate {[Rh(nbd)2]BF4}(41.55 mg, 0.1 mmol), Ligand D (69.73 mg, 0.1 mmol) and the enamine amide 2-4 (45 g, 111.1 mmol) under a nitrogen atmosphere. To this mixture a solvent mixture of 37.5 mL methanol (extra dry and degassed) and 112.5 mL 2,2,2-trifluoroethanol (distilled and degassed) were added. The slurry was then transferred under nitrogen into an stainless steel autoclave and sealed. The autoclave was then heated to 50° C. and pressurized to 500 psig with hydrogen. A sample taken after 17 hours was analyzed using HPLC, which confirmed the end of the reaction giving 94% assay yield and 94% ee.

Provenance & Evidence