Table 1.

Ligand Screen for Asymmetric Hydrogenation of 1a^a

entry	ligand	er (2a)
1	(R)-MP2-Segphos	86.3:13.7
2b	(R)-MP2-Segphos	57.4:42.6
3	(R)-Segphos	91.8:8.2
4	(R)-MeO-Biphep	86.4:13.6
5	(R)-Ph-Garphos	66.5:33.5
6	(R)-Synphos	89.4:10.6
7	(R)-DTBM-Segphos	77.5:22.5
8	(R)-Cyclohexyl Soniphos	84.2:15.8
9c	(R)-tBuPHOX	50.2:49.8
10b,d	(R)-tBuPHOX	53.2:46.8
11	Josiphos-001	54.5:45.5
12	Josiphos-003	50.2:49.8
13b	(S,S)-MeO-BoQphos	99.3:0.7

^aReaction conditions: a mixture of [Ir(COD)Cl]₂ and ligand was stirred in a vial for 15 min in 0.75 mL THF, before addition of 25 mg 1a, 100% conv to the desired product unless specified otherwise.

^b5 mol % of I₂ was added to the catalyst solution before addition of substrate.¹⁰

^c33% conv.

^d40% conv.