Table 7.

Cu(I)-catalyzed cycloaddition of sydnones with terminal alkynes.

entry	R1	R2	R3	ligand (L)	yield [%]	ref.
1	Ph	H	PhCH2CH2	L1 L1 L2	96–98 85a 99	[3,119–120] [118] [3]
2	Ph	H	Ph	L1	80	[3,120]
3	Ph	H	4-MeOPh	L1	64	[3,120]
4	Ph	H	2-Py	L1	95 69a	[3] [118]
5	Ph	H	thiophen-3-yl	L1	95	[3,120]
6	Ph	H	1-heptyl	L1	61	[3,120]
7	Ph	H	PhCOOCH2	L1	93	[3,120]
8	Ph	H	(CH3)2C(OH)	L1	83	[3,120]
9	Ph	H	COOEt	L1	95 51a	[3,120] [118]
10	4-COOH-Ph	H	PhCH2CH2	L1	99	[3,120]
11	4-MeCO-Ph	H	PhCH2CH2	L1	97	[3]
12	4-COOH-Ph	H	(CH3)2C(OH)	L1	93	[3,120]
13	4-COOH-Ph	H		L1	99	[3,120]
14	Ph	H		L1	85	[3]
15	Ph	H		L1	85	[3,120]
16	Ph	H		L1	96	[3,120]
17	Ph	H		L1	62 55a	[3,120] [118]
18	Ph	H		L1	92	[3,120]
19	Ph	H		L1	84	[3,120]
20		H		L1	99	[3,120]
21	Ph	H	Bn–N–Ts	L2	64	[116]
22	4-F-Ph	H	Bn–N–Ts	L2	54	[116]
23	4-CF3-Ph	H	Bn–N–Ts	L2	57	[116]
24	4-MeO-Ph	H	Bn–N–Ts	L2	57	[116]
25	4-MeO-Ph	H	PhCH2CH2	L1	69a	[118]
26	4-Me-Ph	H	PhCH2CH2	L1	72a	[118]
27	4-I-Ph	H	PhCH2CH2	L1	78a	[118]
28	4-NO2-Ph	H	PhCH2CH2	L1	69a	[118]
29	4-CN-Ph	H	PhCH2CH2	L1	92a	[118]
30	4-COOH-Ph	H	PhCH2CH2	L1	85a	[118]
31	4-CF3-Ph	H	PhCH2CH2	L1	80a	[118]
32	3-I-Ph	H	PhCH2CH2	L1	83a	[118]
33	naphthalen-1-yl	H	PhCH2CH2	L1	69a	[118]
34	2-COOMe-thiophen-3-yl	H	PhCH2CH2	L1	50a	[118]
35	Ph	H	Ph	L1	84a	[118]
36	Ph	H	n-pentyl	L1	82a	[118]
37	Ph	H	CH2NHCOO-t-Bu	L1	85a	[118]
38	Ph	H		L1	91a	[118]
39	Ph	Br	PhCH2CH2	L1 L2 L3 L4 L5 L6	74b 67c 60d 75 74 13	[119–120] [119] [119] [119] [119] [119]
40	4-Me-Ph	Br	PhCH2CH2	L4	80	[119]
41	4-MeO-Ph	Br	PhCH2CH2	L4	70	[119–120]
42	4-F-Ph	Br	PhCH2CH2	L4	55	[119]
43	4-I-Ph	Br	PhCH2CH2	L4	72	[119]
44	Ph	Br	COOEt	L4	38	[119]
45	Ph	Br	Ph	L4	63	[119]
46	Ph	Br	6-MeO-naphthalen-2-yl	L4	77	[119]
47	Ph	Br	4-MeO-Ph	L4	44	[119]
48	Ph	Br	CH2NHCOO-t-Bu	L4	69	[119]
49	Ph	Br	CH2OCOPh	L4	52	[119]
50	Ph	Br	BrCH2CH2	L1 L4	45a 63	[119]
51	quinolin-5-yl	Br	PhCH2CH2	L4	33	[119]
52	Ph	Br		L4	52	[119]
53	Ph	Br		L4	65	[119]
54	Ph	Me	PhCH2CH2	L1	7	[119]
55	Ph	Cl	PhCH2CH2	L1	80e	[119]
56	Ph	CN	PhCH2CH2	L1	10f	[119]

^aOne-pot protocol starting from corresponding N-phenyl glycine; ^bratio 1,4,5:1,3,5 is 83:17; ^cratio 1,4,5:1,3,5:1,4,5-debrominated product is 83:10:7; ^dratio 1,4,5:1,3,5:1,4,5-debrominated product is 97:0:3; ^eratio 1,4,5:1,3,5 is 96:4; ^fratio 1,4,5:1,3,5 is 50:50.