L. Liu et al. / Tetrahedron: Asymmetry 22 (2011) 550–557
553
5.0 mmol) and TBDMSCl (0.90 g, 6.0 mmol) afforded 7b 1.82 g
(96.8%) as colorless oil.
J = 7.24 Hz, 1H, NH), 4.31–4.22 (m, 2H, CHNH), 3.59–3.44 (m, 4H,
CH2O), 3.07–3.01 (m, 1H, CH2Ph), 2.96–2.81 (m, 3H, CH2Ph), 0.95
(s, 9H, CH3), 0.82 (s, 9H, CH3), 0.07 (s, 3H, CH3), 0.06 (s, 3H, CH3),
0.01 (s, 3H, CH3), ꢀ0.06 (s, 3H, CH3). 13C NMR (CDCl3, 75 MHz): d
166.94, 163.34, 149.40, 144.76, 138.33, 138.05, 129.47, 129.43,
128.51, 128.34, 126.76, 126.49, 126.29, 125.03, 117.23, 112.43,
62.57, 61.62, 52.53, 52.36, 37.08, 36.59, 25.89, 25.73, 18.22,
18.10, ꢀ5.51, ꢀ5.54, ꢀ5.66. HRMS(ESI): m/z Calcd for C36H53N2O5-
Si2 (M+H+): 677.38005. Found: 677.37994.
a
½
a 2D5
ꢂ
¼ ꢀ85:6 (c 0.25, CH2Cl2). IR
(cmꢀ1): 2953, 2928, 1660, 1523, 1497, 1252, 1117, 1050, 835,
776. 1H NMR (CDCl3, 300 MHz): d 7.75 (s, 1H, CH@), 7.51 (d,
J = 8.43 Hz, 1H, NH), 7.42 (dd, J = 0.48, 5.07 Hz, 1H, ArH), 7.33–
7.15 (m, 11H, ArH), 7.02 (dd, J = 3.69, 5.07 Hz, 1H, ArH), 6.61 (d,
J = 8.34 Hz, 1H, NH), 4.31–4.21 (m, 2H, CHNH), 3.62–3.53 (m, 2H,
CH2O), 3.48 (d, J = 2.97 Hz, 2H, CH2O), 2.99–2.76 (m, 4H, CH2Ph),
0.95 (s, 9H, CH3), 0.80 (s, 9H, CH3), 0.08 (s, 3H, CH3), 0.07 (s,, 3H,
CH3), ꢀ0.02 (s, 3H, CH3), ꢀ0.10 (s, 3H, CH3). 13C NMR (CDCl3,
75 MHz):
d
166.47, 163.70, 138.26, 137.87, 136.37, 132.98,
4.1.6. (S,S)-N,N-Bis(2-TBDMS-1-phenyl)-2-(2-furylmethylidene)
malonamide 8c
131.62, 130.25, 129.46, 128.49, 128.38, 128.02, 127.51, 126.52,
126.35, 62.59, 61.11, 52.50, 52.28, 37.09, 36.47, 25.91, 25.74,
18.24, 18.11, ꢀ5.47, ꢀ5.57, ꢀ5.70. HRMS (ESI): m/z Calcd for
Using the same procedure as described in general procedure I:
dihydroxy diamide 6c (1.14 g, 2.72 mmol), imidazole (0.37 g,
5.0 mmol) and TBDMSCl (0.90 g, 6.0 mmol) afforded 8c 1.65 g
C
38H57N2O4SSi2 (M+H+): 693.35721. Found: 693.35717.
(93.6%) as
a
colorless oil.
½
a 2D5
ꢂ
¼ ꢀ88:0 (c 0.25, CH2Cl2). IR
4.1.3. (S,S)-N,N-Bis(2-TBDMSO-1-phenyl)-2-(2-
thienylmethylidene) malonamide 7c
Using the same procedure as described in general procedure I:
dihydroxy diamide 5c (1.19 g, 2.72 mmol), imidazole (0.37 g,
5.0 mmol) and TBDMSCl (0.90 g, 6.0 mmol) afforded 7c 1.73 g
(cmꢀ1): 2952, 2928, 2856, 1667, 1522, 1464, 1256, 1106, 886,
777. 1H NMR (CDCl3, 300 MHz): d 8.09 (d, J = 7.50 Hz, 1H, NH),
7.50 (s, 1H, CH@), 7.35–7.20 (m, 11H, ArH), 6.95 (d, J = 7.50 Hz,
1H, NH), 6.68 (d, J = 3.45, 1H, ArH), 6.40 (dd, J = 1.80, 1.59 Hz, 1H,
ArH), 5.27–5.23 (m, 1H, CHNH), 5.10–5.07 (m, 1H, CHNH), 3.97–
3.89 (m, 2H, CH2O), 3.86–3.83 (m, 1H, one of CH2O), 3.77–3.72
(m, 1H, one of CH2O), 0.80 (s, 9H, CH3), 0.75 (s, 9H, CH3), ꢀ0.06
(s, 3H, CH3), ꢀ0.12 (s, 3H, CH3), ꢀ0.13 (s, 3H, CH3), ꢀ0.15 (s, 3H,
CH3). 13C NMR (CDCl3, 75 MHz): d 167.16, 163.34, 149.37, 144.99,
140.17, 139.75, 128.31, 128.19, 127.42, 127.17, 127.10, 126.89,
126.58, 125.23, 117.23, 112.34, 66.26, 66.02, 55.15, 54.91, 25.75,
25.70, 18.16, 18.11. HRMS (ESI): m/z Calcd for C36H53N2O5Si2
(M+H+): 649.34875. Found: 649.34900.
(95.8%) as
a
colorless oil.
½
a 2D5
ꢂ
¼ ꢀ35:0 (c 0.25, CH2Cl2). IR
(cmꢀ1): 2954, 2928, 1664, 1523, 1472, 1254, 1108, 851, 743. 1H
NMR (CDCl3, 300 MHz): d 7.81 (d, J = 8.01, 1H, NH), 7.80 (s, 1H,
CH@), 7.40 (dd, J = 0.48, 0.54 Hz, 1H, ArH), 7.27–7.17 (m, 11H,
ArH), 7.14 (d, J = 7.59 Hz, 1H, NH), 6.97 (dd, J = 3.72, 5.04 Hz, 1H,
ArH), 5.20–5.15 (m, 1H, CHNH), 5.11–5.06 (m, 1H, CHNH), 3.97–
3.71 (m, 4H, CH2O), 0.79 (s, 9H, CH3), 0.72 (s, 9H, CH3), ꢀ0.07 (s,
3H, CH3), ꢀ0.15 (s, 6H, CH3), ꢀ0.18 (s, 3H, CH3). 13C NMR (CDCl3,
75 MHz):
d 166.72, 163.51, 140.07, 139.45, 136.33, 132.83,
131.65, 130.21, 128.29, 128.19, 127.89, 127.63, 127.60, 127.41,
127.13, 127.03, 126.96, 126.86, 66.17, 65.57, 65.02, 54.88, 25.82,
25.79, 25.72, 25.65, 25.63, 18.12, 18.09, ꢀ3.60, ꢀ5.71, ꢀ5.76,
ꢀ5.82, ꢀ5.88. HRMS (ESI): m/z Calcd for C36H53N2O4SSi2 (M+H+):
665.32591. Found: 665.32648.
4.2. General procedure II: (S,S)-N,N-bis(2-TBDMSO-1-iso-
propyl)-2-(2-thienylmethylidene) thio-malonamide 9a
To a solution of 7a (1.0 g, 1.68 mmol) in benzene (15.0 mL) was
added Lawesson’s reagent (0.81 g, 2.0 mmol). The mixture was re-
fluxed for 4 h under N2, after which the solvent was removed in va-
cuo. The residue was purified by silica gel column chromatography
(petroleum ether/EtOAc, 9:1) afforded 9a 0.80 g (76.0%) as a pale
4.1.4. (S,S)-N,N-Bis(2-TBDMS-1-iso-propyl)-2-(2-
furylmethylidene) malonamide 8a
Using the same procedure as described in general procedure I:
dihydroxy diamide 6a (0.96 g, 2.72 mmol), imidazole (0.37 g,
5.0 mmol) and TBDMSCl (0.90 g, 6.0 mmol) afforded 8a 151 g.
oil. ½a 2D5
ꢂ
¼ ꢀ155:5 (c 0.25, CH2Cl2). IR (cmꢀ1): 2956, 2928, 2856,
1518, 1500, 1470, 1388, 1254, 1106, 836, 810. 1H NMR (CDCl3,
300 MHz): d 9.50 (d, J = 8.67 Hz, 1H, NH), 8.05 (d, J = 9.03 Hz, 1H,
NH), 7.90 (s, 1H, CH@), 7.40–7.37 (m, 2H, ArH), 7.02 (dd, J = 3.78,
5.01 Hz, 1H, ArH), 4.59–4.51 (m, 2H, CHNH), 3.89–3.71 (m, 4H,
CH2O), 2.15–2.07 (m, 2H, CHMe2), 1.00–0.94 (m, 12H, CH3), 0.91
(s, 9H, CH3), 0.75 (s, 9H, CH3), 0.08 (s, 3H, SiCH3), 0.07 (s, 3H, SiCH3),
ꢀ0.04 (s, 3H, SiCH3), ꢀ0.15 (s, 3H, SiCH3). 13C NMR (CDCl3,
(96.0%) as a colorless oil. ½a D25
¼ ꢀ121:2 (c 0.30, CH2Cl2). IR
ꢂ
(cmꢀ1): 2958, 2929, 2857, 1669, 1620, 1523, 1257, 1107, 835,
776, 740. 1H NMR (CDCl3, 300 MHz): d 7.52 (d, J = 9.27 Hz, 1H,
NH), 7.46 (s, 1H, CH@), 7.43 (d, J = 1.68 Hz, 1H, ArH), 6.74 (d,
J = 3.42 Hz, 1H, ArH), 6.46 (dd, J = 1.80, 3.45 Hz, 1H, ArH), 6.39 (d,
J = 9.48, 1H, NH), 3.93–3.81 (m, 2H, CHNH), 3.84–3.73 (m, 2H,
CH2O), 3.64–3.57 (m, 2H, CH2O), 1.98–1.93 (m, 2H, CHMe2),
0.98–0.93 (m, 12H, CH3), 0.90 (s, 9H, CH3), 0.79 (s, 9H, CH3), 0.05
(s, 3H, CH3), 0.04 (s, 3H, CH3), 0.01 (s, 3H, CH3), ꢀ0.06 (s, 3H,
CH3). 13C NMR (CDCl3, 75 MHz): d 167.38, 163.86, 149.54, 144.64,
127.51, 124.41, 116.73, 112.36, 62.60, 62.26, 56.14, 55.38, 29.15,
28.69, 25.82, 25.66, 19.57, 19.49, 18.91, 18.36, 18.14, 18.03,
ꢀ5.54, ꢀ5.65, ꢀ5.67. HRMS (ESI): m/z Calcd for C30H57N2O5Si2
(M+H+): 581.38005. Found: 581.37990.
75 MHz):
d 195.74, 192.32, 140.04, 136.62, 132.25, 129.70,
129.63, 127.51, 62.68, 61.32, 61.15, 60.24, 28.97, 28.82, 25.93,
25.70, 19.39, 19.11, 19.05, 18.20, 18.14, ꢀ5.37, ꢀ5.63, ꢀ5.69,
ꢀ5.78. HRMS (ESI): m/z Calcd for
C
30H57N2O2S3Si2 (M+H+):
629.31152. Found: 629.31221.
4.2.1. (S,S)-N,N-Bis(2-TBDMSO-1-benzyl)-2-(2-
thienylmethylidene) thio-malonamide 9b
Using the same procedure as described in general procedure II:
7b (1.16 g, 1.68 mmol), and Lawesson’s reagent (0.81 g, 2.0 mmol)
4.1.5. (S)-N,N-Bis(2-TBDMS-1-benzyl)furylmethylidene)
malonamide 8b
afforded 9b 0.83 g (68.0%) as a pale oil. ½a D25
¼ ꢀ112:8 (c 0.25,
ꢂ
CH2Cl2). IR (cmꢀ1): 2952, 2927, 2856, 1509, 1497, 1378, 1252,
1115, 1051, 852, 835, 778. 1H NMR (CDCl3, 300 MHz): d 9.65 (d,
J = 8.01, 1H, NH), 8.06 (d, J = 8.34 Hz, 1H, NH), 7.97 (s, 1H, CH@),
7.40–7.19 (m, 12H, ArH), 7.01 (dd, J = 3.72, 5.07 Hz, 1H, ArH),
4.83–4.81 (m, 2H, CHNH), 3.67–3.56 (m, 4H, CH2O), 3.11–3.05
(m, 2H, CH2Ph), 2.89 (dd, J = 9.18, 13.29 Hz, 1H, one of CH2Ph),
2.78 (dd, J = 10.05, 13.11 Hz, 1H, one of CH2Ph), 0.95 (s, 9H, SiCH3),
0.80 (s, 9H, SiCH3), 0.09 (s, 3H, SiCH3), 0.07 (s, 3H, SiCH3), ꢀ0.03 (s,
3H, SiCH3), ꢀ0.10 (s, 3H, SiCH3). 13C NMR (CDCl3, 300 MHz): d
Using the same procedure as described in general procedure I:
dihydroxy diamide 6b (1.22 g, 2.72 mmol), imidazole (0.37 g,
5.0 mmol) and TBDMSCl (0.90 g, 6.0 mmol) afforded 8b 1.80 g
(98.0%) as
a
colorless oil.
½
a 2D5
ꢂ
¼ ꢀ87:2 (c 0.25, CH2Cl2). IR
(cmꢀ1): 2959, 2928, 1673, 1505, 1475, 1265, 1117, 896, 736. 1H
NMR (CDCl3, 300 MHz): d 7.73 (d, J = 8.46 Hz, 1H, NH), 7.47 (s,
1H, CH@), 7.40 (d, J = 1.59, 1H, ArH), 7.34–7.16 (m, 10H, ArH),
6.71 (d, J = 3.42, 1H, ArH), 6.46–6.42 (m, 1H, ArH), 6.43 (d,