Table 2.

Optimization of reaction conditions for asymmetric cyclopropanation of N-propargyl ynamides 3a

Entry	L	Reaction conditions	Yield (%)a	Ee (%)b
1	L1	DCM, 35 °C, 0.5 h	88	68
2	L2	DCM, 35 °C, 0.5 h	90	54
3	L3	DCM, 35 °C, 0.5 h	61	<5
4	L4	DCM, 35 °C, 0.5 h	63	33
5	L5	DCM, 35 °C, 0.5 h	88	83
6	L6	DCM, 35 °C, 0.5 h	92	90
7	L10	DCM, 35 °C, 0.5 h	78	82
8	L11	DCM, 35 °C, 0.5 h	80	90
9	L12	DCM, 35 °C, 0.5 h	93	92
10	L12	toluene, 35 °C, 0.5 h	85	93
11	L12	THF, 35 °C, 0.5 h	94	93
12	L12	2-MeTHF, 35 °C, 3 h	95	94
13	L12	2-MeTHF, 0 °C, 40 h	95	96

Reaction conditions: 3a (0.05 mmol), Cu(MeCN)₄PF₆ (0.005 mmol), L (0.006 mmol), NaBAr^F₄ (0.006 mmol), solvent (1 mL), in Schlenk tubes

^aMeasured by ¹H NMR using diethyl phthalate as internal standard.

^betermined by HPLC analysis. NTHP = 1-pyrrolidinyl, 2-MeTHF = 2-methyltetrahydrofuran.