Table 3. Enantioselective Cu-Catalyzed α-Chlorination of β-Keto Ester.

entry	ligand	temp (°C)	yield (%)	% ee
1	546	rt	99	47
2	547	rt	99	78
3	548a	rt	99	78
4	548b	rt	95	50
5	548c	rt	99	54
6	548d	rt	99	68
7	548a	0	99	83
8	548a	–20	99	72
9	548a	–78	99	6