Table 1.

Initial optimization with trans-β-nitrostyrene^a

entry	ligand	solvent	% yield	% ee
1	L1	toluene	85	−3
2	L2	toluene	70	18
3	L3	toluene	79	53
4	L4	toluene	79	84
5	L5	toluene	93	87
6	L5	dioxane	79	85
7	L5	THF	57	91

^aAll reactions were conducted at 0.15 M in the indicated solvent, at 50 °C, with 1.6 equiv of 1a, 5% Pd(dba)₂ and 10% ligand. Yields are isolated values; ee’s were determined by chiral HPLC.