Table 1.

Ligand Effect on Co(II)-Based Metalloradical System for Asymmetric 1,5-C–H Amination of Arylsulfonyl Azide^a

entry	catalyst	temp (°C)	solvent	yield (%)	ee (%)
1	[Co(P1)]	80	chlorobenzene	99	28
2	[Co(P2)]	80	chlorobenzene	99	32
3	[Co(P3)]	80	chlorobenzene	99	49
4	[Co(P4)]	80	chlorobenzene	99	84
5	[Co(P4)]	60	chlorobenzene	99	86
6	[Co(P4)]	40	chlorobenzene	63	88
7	[Co(P4)]	60	chloroform	70	89
8b	[Co(P4)]	50	chloroform	96	92

^aReactions were carried out for 18 h on 0.10 mmol scale under N₂; [1a] = 0.25 M. Isolated yields Enantiomeric excess determined by chiral HPLC.

^b4 mol % catalyst for 48 h.