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. Author manuscript; available in PMC: 2010 Nov 1.
Published in final edited form as: Synthesis (Stuttg). 2010 May 1;2010(9):1441–1448. doi: 10.1055/s-0029-1218683

Table 2.

Scope of the Copper(II)-Catalyzed Azidation of Arylboronic Acids

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Entry R σpa Product Yieldb (%)
1 4-OMe −0.27 2a 78 ± 5
2 4-OPh −0.03 2b 92 ± 8
3 4-Ph −0.01 2c 50 ± 1
4 4-CH2OH 0 2d 98 ± 1
5 H 0 3e 64c
6 4-SMe 0 2f 97 ± 1
7 4-F +0.06 3g 68c
8 4-I +0.18 2h 63 ± 2
9 4-Cl +0.23 2i 73 ± 4
10 4-Br +0.23 2j 68 ± 6
11 4-CONH2 +0.36 2k 84 ± 3
12 4-CHO +0.42 2l 81 ± 4
13 4-CO2H +0.45 2m 89 ± 3
14 4-CO2Me +0.45 2n 99 ± 0
15 4-COMe +0.50 2o 81 ± 3
16 4-CF3 +0.54 3p 68c
17 4-CN +0.66 2q 98 ± 1
18 4-SO2Me +0.72 2r 86 ± 3
19 4-NO2 +0.78 2s 85 ± 1
20 3-Ph –d 2t 46 ± 1
21 2-Ph –d 2u 40 ± 2
22 2-NHCOt-Bu –d 2v 94 ± 2
a

Hammett substituent constants.11

b

Isolated yield ± standard deviation from 2–3 independent experiments.

c

Due to volatility, the crude azides were not isolated, but reacted in situ with methyl propiolate to afford the corresponding triazoles 3. The isolated yields are for the corresponding triazole products. See experimental section for details.

d

Not applicable.