Table 2. Optimization of the enantioselective aminocyclopropane activation ^a .

Entry	L*	RCO2H	% yield of 4b b	er c
1	L1	AdCO2H	2	n.d.
2	L2	AdCO2H	99	93.5 : 6.5
3	L3	AdCO2H	55	85.5 : 14.5
4	L4	AdCO2H	94	90 : 10
5	L5	AdCO2H	99	93 : 7
6	L2	—	3	n.d.
7	L2	AcOH	86	60 : 40
8	L2	XanthCO2H	25	77 : 23
9	L2	PivOH	92	92.5 : 7.5
10 d	L2	AdCO2H	99	93.5 : 6.5
11 e	L2	AdCO 2 H	96 (93)	93.5 : 6.5

^aReaction conditions: 0.05 mmol 3b, 5.0 mol% Pd(dba)₂, 10 mol% L*, 20 mol% RCO₂H, 1.5 equiv. Cs₂CO₃ 0.1 M in toluene, 110 °C, 12 h.

^bDetermined by ¹H-NMR with an internal standard (isolated yield in parentheses).

^cer values were determined by HPLC with a chiral stationary phase.

^dWith K₂CO₃ instead of Cs₂CO₃.

^eWith 2.5 mol% Pd(dba)₂, 5.0 mol% L2, 0.25 M in toluene.