Table 1. Cu2+-nitrile-mediated activation of A′3P and effect of Gly or GlyGly.
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Entry | Nitrile | R | Yield of 3 or 2′-transfer adducts
a
(%) |
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CuCl2 |
CuCl2 and Gly |
CuCl2 and GlyGly |
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3 b | 2′-adduct | 3 b | 2′-adduct | 3 b | 2′-adduct | |||
1 | 1 | 84 | n.d. c | 85 d | n.d. | 80 | n.d. | |
2 | 4 | n.d. | n.d. | n.d. | n.d. | n.d. | n.d. | |
3 | 5 | n.d. | n.d. | n.d. | n.d. | n.d. | n.d. | |
4 | 6 | 5 | n.d. | 2 | n.d. | n.d. | n.d. | |
5 | 7 | 24 | 15 | 21 | 8 | 23 | 5.4 | |
6 | 8 | 53 | 6 | 50 | 4 | 97 e | 3 | |
7 | 10 | 75 | n.d. | 60 | n.d. | 5 | n.d. | |
8 | 11 | 35 | n.d. | 22 | n.d. | 34 | n.d. |
aStandard reaction conditions: nitrile (100 mM), 2 (50 mM), CuCl2 (25 mM) and Gly or GlyGly (50 mM) in 90% H2O, 10% D2O at pH 4 (entries 1, 5 and 8) or pH 5.5 (entries 2, 3, 4, 6 and 7), heated at 40 °C for 20 hours.
bInferred from the amount of 3 plus adenosine 2′-phosphate A2′P 12, assuming that when 3 hydrolyses it always gives 2 and 12 in 1.8 : 1 ratios.17
cNot detected.
dInitial pH 5.5.
eInitial pH 4.