Table 1.

Selected optimization conditions^a

entry	ligand	solvent	% yieldb	% eec
1	L1	DCE	73	61
2	L2	DCE	99	89
3	L3	DCE	77	72
4	L4	DCE	<5	9
5	L2	PhMe	50	89
6	L2	PhCF3	52	88
7	L2	THF	52	89
8	L2	DME	44	89
9	L2	Dioxane	60	93

^aAll reactions were performed with 1.0 equiv of 2a and 1.1 equiv of 1a at ambient temperature at 0.25M in the designated solvent.

^bIsolated yield.

^c% ee determined by chiral HPLC.