M. Fantinel, N. Valiati, P.A.M. Moro et al.
Tetrahedron 86 (2021) 132081
(C]O), 185.2 (C]O), 137.5 (C), 132.8 (CH), 129.1 (2 ꢂ CH), 127.5
(2 ꢂ CH), 29.3 (CH3). IR (KBr, cmꢀ1): nmax ¼ 3107, 2929, 2123, 1656,
1640, 1322, 1234, 716. HRMS (ESIþ) calcd. for C10H8N2O2Naþ [M þ
Na]þ: 211.0478, found: 211.0480.
4.3.11. Ethyl 4-chloro-2-diazo-3-oxobutanoate (2k) [27a]
Yellow oil. PS1-NH2: reaction time ¼ 4 h, yield 77% (147 mg);
PS2-NH2: reaction time ¼ 8 h, yield 79% (150 mg). 1H NMR
(200 MHz, CDCl3):
d
4.60 (s, 2H), 4.31 (q, J ¼ 7.1 Hz, 2H), 1.33 (t,
J ¼ 7.1 Hz, 3H). IR (KBr, cmꢀ1): nmax ¼ 2984, 2142, 1715, 1671, 1336,
1293, 1216, 1028.
4.3.3. 2-Diazo-1,3-diphenylpropane-1,3-dione (2c) [6g]
Yellow solid, m.p. 106.3e107.1 ꢁC (lit.: [6g] 107.8e108.2 ꢁC). PS1-
NH2: reaction time ¼ 8 h, mixture of 2c, 3, and 1c (1.7:2.5:1 ratio);
PS2-NH2: reaction time ¼ 16 h, yield 65% (162 mg). 1H NMR
4.3.12. Ethyl 2-diazo-3-oxo-3-phenylpropanoate (2l) [6f]
Pale yellow oil. PS1-NH2: reaction time ¼ 5 h, yield 91%
(400 MHz, CDCl3):
d
7.57 (d, J ¼ 7.5 Hz, 4H), 7.44 (t, J ¼ 7.5 Hz, 2H),
(198 mg); PS2-NH2: reaction time ¼ 8 h, yield 73% (159 mg). 1H
7.32 (t, J ¼ 7.5 Hz, 4H). 13C NMR (100 MHz, CDCl3):
186.6 (2 ꢂ C]
d
NMR (400 MHz, CDCl3):
d 7.64e7.60 (m, 2H), 7.54e7.48 (m, 1H),
O), 137.1 (2 ꢂ C), 132.8 (2 ꢂ CH), 128.5 (4 ꢂ CH), 128.4 (4 ꢂ CH). IR
(KBr, cmꢀ1): nmax ¼ 3054, 2113, 1636, 1593, 1261, 855, 716. HRMS
(ESIþ) calcd. for C15H10N2O2Naþ [M þ Na]þ: 273.0634, found:
273.0630.
7.44e7.38 (m, 2H), 4.23 (q, J ¼ 7.1 Hz, 2H), 1.24 (t, J ¼ 7.1 Hz, 3H). 13
C
NMR (100 MHz, CDCl3): d 187.0 (C]O), 161.1 (C]O), 137.2 (C), 132.3
(CH), 128.4 (2 ꢂ CH), 127.9 (2 ꢂ CH), 61.7 (CH2), 14.3 (CH3). IR (KBr,
cmꢀ1): nmax ¼ 3062, 2984, 2144, 1724, 1693, 1630, 1301, 1116, 938,
747. HRMS (ESIþ) calcd. for C11H10N2O3Naþ [M þ Na]þ: 241.0584,
found: 241.0579.
4.3.4. 2-Diazo-5,5-dimethylcyclohexane-1,3-dione (2d) [6c]
Yellow solid, m.p. 103.6e104.0 ꢁC decomp. (lit. [6c]:
103e105 ꢁC). PS1-NH2: reaction time ¼ 1 h, yield 96% (159 mg);
PS2-NH2: reaction time ¼ 2 h, yield 94% (156 mg). 1H NMR
4.3.13. Ethyl 2-diazo-3-(4-nitrophenyl)-3-oxopropanoate (2m) [15]
Pale yellow solid, m.p. 39.7e40.8 ꢁC (lit. [6e,15]: colorless oil).
PS2-NH2: reaction time ¼ 5 h, yield 87% (229 mg). 1H NMR
(200 MHz, CDCl3):
d
2.44 (s, 4H), 1.12 (s, 6H). IR (KBr, cmꢀ1):
nmax ¼ 2962, 2189, 2136, 1673, 1636, 1307.
(200 MHz, CDCl3):
d
8.26 (d, J ¼ 8.8 Hz, 2H), 7.74 (d, J ¼ 8.8 Hz, 2H),
4.23 (q, J ¼ 7.1 Hz, 2H), 1.25 (t, J ¼ 7.1 Hz, 3H). 13C NMR (50 MHz,
4.3.5. 2-Diazocyclohexane-1,3-dione (2e) [6e]
Pale yellow oil. PS1-NH2: reaction time ¼ 3 h, yield 86%
CDCl3):
d 185.7 (C]O), 160.4 (C]O), 149.7 (C), 142.7 (C), 129.4
(119 mg); PS2-NH2: reaction time ¼ 5 h, yield 68% (94 mg). 1H NMR
(2 ꢂ CH), 123.2 (2 ꢂ CH), 62.1 (CH2), 14.3 (CH3). IR (KBr, cmꢀ1):
nmax ¼ 3080, 2984, 2148, 1720, 1630, 1601, 1524, 1314, 1118, 853.
HRMS (ESIþ) calcd. for C11H9N3O5Naþ [M þ Na]þ: 286.0434, found:
286.0429.
(400 MHz, CDCl3):
d
2.54 (t, J ¼ 6.5 Hz, 4H), 2.08e1.95 (m, 2H). 13
C
NMR (100 MHz, CDCl3):
d
190.5 (2 ꢂ C]O), 36.9 (2 ꢂ CH2), 18.7
(CH2). IR (KBr, cmꢀ1): nmax ¼ 2958, 2138, 1640, 1293.
4.3.6. 5-Diazo-2,2-dimethyl-1,3-dioxane-4,6-dione (2f) [6b]
White solid, m.p.: 90.0e91.1 ꢁC (lit. [6b]: 92e93 ꢁC). PS1-NH2:
reaction time ¼ 2 h, yield 76% (129 mg); PS2-NH2: reaction
4.3.14. Allyl 2-diazo-3-oxobutanoate (2n) [30]
Pale yellow oil. PS2-NH2: reaction time ¼ 3 h, yield 69%
(116 mg). 1H NMR (400 MHz, CDCl3):
d
5.92 (ddt, J ¼ 17.2, 10.4,
time ¼ 2 h, yield 67% (114 mg). 1H NMR (200 MHz, CDCl3):
d 1.79 (s,
6H). IR (KBr, cmꢀ1): nmax ¼ 2990, 2183, 1726, 1336, 1167, 908, 757.
5.8 Hz, 1H), 5.33 (dq, J ¼ 17.2, 1.3 Hz, 1H), 5.27 (dq, J ¼ 10.4, 1.3 Hz,
1H), 4.71 (dt, J ¼ 5.8, 1.3 Hz, 2H), 2.46 (s, 3H). 13C NMR (100 MHz,
CDCl3):
d 190.1 (C]O), 161.2 (C]O), 131.6 (CH), 119.2 (CH2), 65.9
4.3.7. Dimethyl 2-diazomaloante (2g) [6g]
(CH2), 28.3 (CH3). IR (KBr, cmꢀ1): nmax ¼ 2952, 2142, 1720, 1658,
Colorless oil. PS1-NH2: reaction time ¼ 24 h, yield 57%
(90.1 mg); PS2-NH2: reaction time ¼ 24 h, yield 59% (93.3 mg). 1H
NMR (200 MHz, CDCl3): 3.83 (s, 6H). IR (KBr, cmꢀ1): nmax ¼ 2958,
2138, 1762, 1742, 1697, 1438, 1334, 1097, 761.
1369, 1314, 1067.
4.3.15. Prop-2-yn-1-yl 2-diazo-3-oxobutanoate (2o) [31]
Pale yellow oil. PS2-NH2: reaction time ¼ 3 h, yield 63%
4.3.8. Methyl 2-diazo-3-oxobutanoate (2h) [9a]
(104 mg). 1H NMR (400 MHz, CDCl3):
d
4.81 (d, J ¼ 2.5 Hz, 2H), 2.53
Colorless oil. PS1-NH2: reaction time ¼ 3 h, yield 62% (88.1 mg);
(t, J ¼ 2.5 Hz, 1H), 2.46 (s, 3H). 13C NMR (100 MHz, CDCl3):
d 189.8
PS2-NH2: reaction time ¼ 8 h, yield 65% (92.4 mg). 1H NMR
(C]O), 160.7 (C]O), 77.0 (C), 75.8 (CH), 52.7 (CH2), 28.3 (CH3). IR
(KBr, cmꢀ1): nmax ¼ 3284, 2952, 2144, 1724, 1658, 1318, 1069. HRMS
(ESIþ) calcd. for C7H6N2O3Naþ [M þ Na]þ: 189.0271, found:
189.0267.
(200 MHz, CDCl3):
d
3.81 (s, 3H), 2.45 (s, 3H). IR (KBr, cmꢀ1):
nmax ¼ 2958, 2142, 1724, 1660, 1316, 1081.
4.3.9. Ethyl 2-diazo-3-oxobutanoate (2i) [6f]
Colorless oil. PS1-NH2: reaction time ¼ 4 h, yield 80% (125 mg);
PS2-NH2: reaction time ¼ 8 h, yield 58% (90.5 mg). 1H NMR
4.4. Reutilization of the catalyst PS-NH2
(200 MHz, CDCl3):
d
4.24 (q, J ¼ 7.1 Hz, 2H), 2.41 (s, 3H), 1.27 (t,
J ¼ 7.1 Hz, 3H). IR (KBr, cmꢀ1): nmax ¼ 2984, 2140, 1720, 1660, 1318,
At the end of the diazo transfer reaction, the catalyst was
separated by vacuum filtration and was quantitatively recovered
after exhaustive washings with methanol and dichloromethane
followed by drying under vacuum. Next, 300 mg of the catalyst was
suspended in 6 mL of DMF (2 mL/100 mg of catalyst) and ~3 mL of
TFA was slowly added to the suspension. The mixture was
magnetically stirred at room temperature for 30 min. Then the
catalyst was filtered by vacuum using a Büchner funnel and thor-
oughly washed with a solution of TEA (2.0 mL) in DMF (20 mL)
followed by successive washings with H2O, methanol, acetone and
dichloromethane. The recovered catalyst was dried under vacuum
for 3e4 h before its utilization in the next cycle.
1075.
4.3.10. Ethyl 2-diazo-3-oxopentanoate (2j) [29]
Yellow oil. PS1-NH2: reaction time ¼ 8 h, yield 65% (110 mg);
PS2-NH2: reaction time ¼ 16 h, yield 81% (138 mg). 1H NMR
(200 MHz, CDCl3):
d
4.28 (q, J ¼ 7.0 Hz, 2H), 2.84 (q, J ¼ 7.2 Hz, 2H),
1.31 (t, J ¼ 7.0 Hz, 3H), 1.12 (t, J ¼ 7.2 Hz, 3H). 13C NMR (50 MHz,
CDCl3):
d 193.7 (C]O), 161.6 (C]O), 61.5 (CH2), 33.8 (CH2), 14.4
(CH3), 8.4 (CH3). IR (KBr, cmꢀ1): nmax ¼ 2982, 2134, 1720, 1660, 1301,
1026. HRMS (ESIþ) calcd. for C7H10N2O3Naþ [M þ Na]þ: 193.0584,
found: 193.0584.
8