Table 2. The ligand effect of terpyridine–Cu(ii) cofactor on the catalytic function of human telomeric G-quadruplex DNA metalloenzyme.

Entry	Ligand	Conv. a (%)	endo/exo b	ee b (%, endo)
1	L1	99	99/1	94
2	L2	99	98/2	93
3	L3	99	97/3	92
4	L4	95	98/2	93
5	L5	37	81/19	18
6	L6	25	68/32	6

^aDetermined for the crude product by HPLC analysis on a chiral stationary phase (ESI note 5), reproducible within ±2%.

^bDetermined by chiral-phase HPLC. Reproducible within ±2%. Reaction conditions: 1a (1 mM), 2 (10 μL, 260 mM), HT21 (50 μM), Cu(Ln)(NO₃)₂ (100 μM), NH₄Cl (30 mM), MOPS buffer (0.5 mL, 20 mM, pH 6.5), 4 °C, 24 h.