538
T. K. Ellis, V. A. Soloshonok
LETTER
J = 6.3 Hz), 2.76 (1 H, br s), 3.12 (1 H, dq, J = 13.2, 6.3 Hz),
3.29 (1 H, d, J = 17.7 Hz), 3.75 (2 H, s), 3.99 (1 H, dd,
J = 17.7, 7.5 Hz), 6.83 (1 H, m), 6.93 (1 H, m), 7.01 (1 H, m),
7.19 (1 H, m), 7.35 (1 H, m), 7.53–7.59 (3 H, m), 8.55 (1 H,
d, J = 7.8 Hz). 13C NMR (75.42 MHz, CDCl3): d = 20.57,
21.74, 51.70, 53.33, 60.60, 121.28, 128.34, 125.69, 125.82,
136.24, 129.45, 129.75, 129.88, 132.66, 133.60, 134.66,
142.62, 173.23, 177.88, 177.91, 178.18. HRMS: m/z calcd
for C20H21N3NaNiO3: 432.0828; found: 432.0837.
Hz), 2.67 (1 H, s), 2.74 (1 H, h, J = 6.6 Hz), 2.86 (1 H, d,
J = 16.5 Hz), 3.18–3.30 (2 H, m), 3.56 (1 H, dd, J = 18.6, 8.7
Hz), 3.72 (1 H, dd, J = 18.6, 8.7 Hz), 4.20 (1 H, dd, J = 8.7,
3.9 Hz), 4.49 (1 H, d, J = 4.5 Hz), 4.63 (1 H, t, J = 9.0 Hz),
5.18 (1 H, dd, J = 8.7, 3.9Hz), 6.74 (1 H, d, J = 2.7 Hz),
6.99–7.05 (3 H, m), 7.24 (1 h, d, J = 2.7 Hz), 7.27 (1 H, d,
J = 2.7 Hz), 7.28–7.33 (5 H, m), 7.37 (1 H, t, J = 7.2 Hz),
7.47–7.52 (3 H, m), 7.56–7.62 (3 H, m), 8.40 (1 H, d, J = 9.3
Hz). 13C NMR (75.42 MHz, CDCl3): d = 20.22, 21.44, 29.30,
44.95, 52.75, 53.78, 57.47, 69.77, 73.29, 124.67, 125.66,
125.91, 127.27, 127.95, 128.31, 128.42, 128.49, 128.75,
128.88, 129.33, 129.42, 130.32, 130.80, 132.57, 132.70,
132.86, 138.82, 139.21, 141.57, 153.35, 169.80, 169.98,
176.94, 177.08. HRMS: m/z calcd for C38H36N4NaNiO6:
759.1501; found: 759.1584.
Compound 9c: mp >300 °C (decomp.). 1H NMR (299.95
MHz, CDCl3): d = 1.54 (9 H, s), 2.60 (1 H, d, J = 7.8 Hz),
3.41 (1 H, d, J = 17.1 Hz), 3.73 (2 H, d, J = 3.9 Hz), 4.17 (1
H, dd, J = 17.1, 7.5 Hz), 6.84 (1 H, m), 6.93 (1 H, dd, J = 8.1,
1.8 Hz), 6.99 (1 H, m), 7.23 (1 H, m), 7.38 (1 H, m), 7.53–
7.60 (3 H, m), 8.37 (1 H, d, J = 7.5 Hz). 13C NMR (75.42
MHz, CDCl3): d = 28.02, 50.98, 58.25, 60.42, 121.33,
124.24, 125.71, 126.27, 129.41, 129.79, 129.90, 132.72,
133.50, 134.54, 142.38, 171.74, 177.36, 177.72. HRMS:
m/z calcd for C21H23N3NaNiO3: 446.0985; found: 446.1015.
The Michael Addition of the Oxazolidinone Derived
Amides of Cinnamic Acid and Nucleophilic Glycine
Equivalents 9a–c; General Procedure.
To a flask containing 9a, 9b, or 9c (0.10 g), 3-[(E)-3-alkyl-
acryloyl]oxazolidin-2-one 20a,b (1.05 equiv) and 3 mL of
DMF, DBU (15 mol%) was added to the reaction mixture,
which was stirred at r.t. and monitored by TLC. After
disappearance of starting glycine equivalent by TLC, the
reaction mixture was poured into a beaker containing 100
mL ice water. After the ice had melted the corresponding
product 21a,b, 22, 23, was filtered from the aqueous solution
and dried in an oven to afford the corresponding product in
high chemical yields.
Compound 21b: mp 183.1 °C. 1H NMR (299.95 MHz,
CDCl3): d = 1.28 (9 H, s), 2.67 (1 H, s), 2.97 (1 H, d, J = 16.8
Hz), 3.20–3.37 (2 H, m), 3.51 (1 H, dd, J = 17.7, 8.4 Hz),
3.74 (1 H, dd, J = 17.7, 8.4 Hz), 4.17 (1 H, dd, J = 9, 3.9 Hz),
4.46 (1 H, d, J = 4.5 Hz), 4.61 (1 H, t, J = 8.7 Hz), 5.18 (1 H,
dd, J = 8.7, 3.6 Hz), 6.79 (1 H, m), 6.98–7.03 (3 H, m), 7.26–
7.38 (7 H, m), 7.43–7.49 (3 H, m), 7.54–7.63 (4 H, m), 8.23
(1 H, d, J = 8.4 Hz). 13C NMR (75.42 MHz, CDCl3): d =
27.78, 36.55, 44.93, 50.81, 57.45, 59.70, 69.72, 72.53,
120.89, 123.10, 125.81, 127.34, 127.63, 128.24, 128.32,
128.82, 128.87, 129.03, 129.18, 129.97, 130.62, 132.88,
133.62, 133.94, 138.83, 139.11, 142.79, 153.29, 169.99,
170.83, 176.36, 177.20. HRMS: m/z calcd for
C39H39N4NiO6: 739.2037; found: 739.2078.
Compound 21a: mp 153.7 °C. 1H NMR (299.95 MHz,
CDCl3): d = 1.43 (9 H, s), 1.91 (3 H, s), 3.04 (1 H, dd,
J = 18.3, 7.2 Hz), 3.24 (1 H, dd, J = 18.3, 7.2 Hz), 3.39 (1 H,
d, J = 17.1 Hz), 4.16 (1 H, d, J = 4.5 Hz), 4.22 (1 H, dd,
J = 9.0, 3.6 Hz), 4.39 (1 H, q, J = 17.1, 7.2 Hz), 4.61 (1 H, t,
J = 8.7 Hz), 5.28 (1 H, dd, J = 8.7, 3.3 Hz), 6.78 (2 H, d,
J = 4.8 Hz), 6.94 (1 H, d, J = 7.8 Hz), 7.25 (2 H, m), 7.30–
7.47 (7 H, m), 7.53 (1 H, t, J = 7.8 Hz), 8.37 (1 H, d, J = 8.4
Hz). 13C NMR (75.42 MHz, CDCl3): d = 16.85, 27.97, 33.75,
38.94, 51.51, 57.50, 57.89, 69.93, 72.32, 120.98, 123.04,
126.09, 127.33, 127.81, 128.59, 128.83, 129.03, 129.09,
129.85, 132.88, 133.68, 134.00, 139.23, 142.73, 153.55,
170.46, 171.24, 177.12, 177.78. HRMS: m/z calcd for
C34H36N4NiO6: 677.1880; found: 677.1918.
Compound 23: mp 146.3 °C. 1H NMR (299.95 MHz,
CDCl3): d = 2.66–2.89 (4 H, m), 3.25–3.42 (3 H, m), 3.85 (1
H, dd, J = 16.2, 6.0 Hz), 4.18 (1 H, dd, J = 8.7, 3.9 Hz), 4.43
(1 H, d, J = 4.2 Hz), 4.60 (1 H, t, J = 8.7 Hz), 5.18 (1 H, dd,
J = 8.7, 3.9 Hz), 6.71–6.84 (3 H, m), 6.97–7.01 (2 H, m),
7.05 (1 H, d, J = 6.9 Hz), 7.11–7.14 (2 H, m), 7.23–7.47 (10
H, m), 7.56–7.59 (2 H, m), 7.67–7.73 (3 H, m), 8.38 (1 H, d,
J = 8.7 Hz). 13C NMR (75.42 MHz, CDCl3): d = 36.44,
45.18, 53.08, 54.69, 57.47, 69.75, 73.38, 121.04, 123.85,
125.72, 125.86, 126.88, 126.96, 127.24, 127.97, 128.28,
128.37, 128.74, 128.89, 129.14, 129.62, 129.79, 130.72,
132.57, 133.53, 133.61, 133.98, 138.72, 132.84, 139.24,
142.93, 169.89, 171.02, 175.94, 176.60, 177.47. HRMS:
m/z calcd for C42H36N4NaNiO6: 773.1880; found: 773.1813.
Compound 22: mp 183.1 °C. 1H NMR (299.95 MHz,
CDCl3): d = 1.29 (3 H, d, J = 6.6 Hz), 1.37 (3 H, d, J = 6.6
(12) For the general procedure for the disassembly of the Ni(II)
Schiff base complexes see: (a) Soloshonok, V. A.; Ueki, H.;
Ellis, T. K.; Yamada, T.; Ohfune, Y. Tetrahedron Lett. 2005,
46, 1107. (b) Ellis, T. K.; Ueki, H.; Soloshonok, V. A.
Tetrahedron Lett. 2005, 46, 941.
Synlett 2006, No. 4, 533–538 © Thieme Stuttgart · New York