Table 1. Selected optimization results.

Entry	Rh-source	X	Additive	I+ source	Y	Temp/°C	Z	2a : 3a : 4
1	[RhCp*Cl2]2 (2.5%)	10	Cu(OAc)2	NIS	220	120	22	39 : 8 : 0
2	[RhCp*Cl2]2 (2.5%)	10	Cu(OAc)2	DIH	140	120	22	4 : 14 : 10
3	[RhCp*Cl2]2 (2.5%)	10	Cu(OPiv)2	NIS	140	120	22	14 : 0 : 0
4	[RhCp*Cl2]2 (2.5%)	10	Zn(OAc)2	NIS	140	120	22	18 : 0 : 0
5	[RhCp*Cl2]2 (4%)	10	Cu(OAc)2	NIS	120	100	16	44 : 5 : 0
6	[RhCp*i-prCl2]2 (4%)	10	Cu(OAc)2	NIS	120	100	16	39 : 8 : 0
7	[RhCp*CF3Cl2]2 (4%)	10	Cu(OAc)2	NIS	120	100	16	3 : 0 : 0
8	[RhCp*(OAc)2] (4%)	10	Cu(OAc)2	NIS	120	100	16	32 : 2 : 0
9	[RhCp*Cl2]2 (4%)	10	Cu(OAc)2	NIS	120 50 a	(65 W)	2.5	54 : 0 : 14
10	[RhCp*Cl2]2 (3.75%)	20	Cu(OAc)2	NIS	100 45 a	(60 W)	2	69 : 0 : 5

^aExternal temperature of the reaction vessel. NIS = N-iodosuccinimide. DIH = 1,3-diiodo-5,5-dimethylhydantoin. Cp*^i-Pr = isopropyl tetramethylcyclopentadienyl. Cp*^CF₃ = trifluoromethyl tetramethylcyclopentadienyl.