. 2018 Jun 4;9(26):5767–5772. doi: 10.1039/c8sc02041h

Table 1. Ligand screening and reaction optimization ^a .


Entry	Ligand	Solvent	Base	t [h]	Yield ^b [%]	er ^c
1	L1	DCE	—	48	(22)	92.5 : 7.5
2	L1	DCE	Cs₂CO₃	48	<5	n.d.
3	L1	DCE	DBU	48	<5	n.d.
4	L1	DCE	i-Pr₂NEt	48	72	96 : 4
5	L1	DCE	Et₃N	48	74	97 : 3
6	L1	DCE	i-Pr₂NH	48	76	97 : 3
7	L1	DCE	DABCO	48	84	97.5 : 2.5
8	L2	DCE	DABCO	48	<5	n.d.
9	L3	DCE	DABCO	48	11	98 : 2
10	L4	DCE	DABCO	48	<5	n.d.
11	L5	DCE	DABCO	48	28	92 : 8
12	L1	THF	DABCO	48	11	96 : 4
13	L1	CHCl₃	DABCO	48	67	97 : 3
14	L1	CH₂Cl₂	DABCO	36	88 (86)	98 : 2

^aReaction conditions: 3 mol% [Ir(COD)Cl]₂, 6 mol% ligand, 0.24 mmol of 1a, 0.2 mmol of 2a and 0.2 mmol of base in 0.6 mL solvent. The catalyst was prepared via n-PrNH₂ activation.

^bYields were determined by ¹H-NMR spectroscopy with mesitylene as the internal standard. Isolated yields are given in the parentheses.

^cThe enantiomeric ratio (er) was determined by HPLC analysis on a chiral stationary phase; n.d. = not determined. DCE = 1,2-dichloroethane.

Table 1. Ligand screening and reaction optimization a .

Table 1. Ligand screening and reaction optimization ^a .