Table 4.

N–H insertion reaction scope with donor/donor metal carbenes

entry[b]	R1	R2	R3	catalyst	# examples	yield (%)	ref.
1	aryl	H, alkyl	H, alkyl, aryl	[Cu], 32	40	50–93	18
2	alkyl	H, alkyl	aryl	[Ru], 29	10	10–48	65
3	alkyl	H, alkyl	H, alkyl, aryl	[Cu], 30, 32	23	40–84	18,41,67
4[c]		imidazoles	H, aryl	[Cu], 32	10	50–80	66
5[d]	COR	H	H	[Cu], 33	38	33–99	68
6	COR	H, alkyl, aryl	alkyl/aryl	[Cu], 31, 33	38	40–98	42,68
7	imidazole, carbazole, morpholine		Ph	[Fe], 38	3	86–94	64
8	Ph, Bn	H	Ph	[Fe], 38	2	51–56	64

^[a]includes Ar = 2-pyridyl napthyl (entry 1); Ar/R³ = fluorenyl (entry 2); Ar = napthyl (entries 5 and 6).

^[b]diazo compounds for all entries except 7 and 8 are derived from tosylhydrazones

^[c]includes 2 examples with cyclohexanone-derived tosylhydrazones.

^[d]includes 3 examples with tosylhydrazones derived from alkyl aldehydes.