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F.-X. Chen et al / Tetrahedron 60 (2004) 10449–10460
4.2.6. (1R,2R)-N,N0-Bis(50-methoxy-salicylidene)-1,2-
diphenyl-ethylenediimine (1f). Mp 91–93 8C, [lit. 89–
91 8C for (1S,2S)-1f].14 1H NMR (400 MHz, CDCl3): 3.70
(s, 6H, 2CH3O), 4.71 (s, 2H, CH–CH), 6.64 (s, 2H, aromatic
H), 6.89 (m, 4H, aromatic H), 7.16–7.21 (m, 10H, aromatic
H), 8.26 (s, 2H, 2CH]N), 12.82 (s, 2H, 2ArOH); 13C NMR
(100 MHz, CDCl3): 55.8, 80.3, 114.9, 117.6, 118.1, 119.8,
127.6, 127.8, 128.4, 139.3, 152.0, 155.1, 165.9; [a]2D2Z
K12.0 (cZ3.58, CH2Cl2), {lit. [a]2D0ZC4.9 (cZ4.0,
CH2Cl2, for (1S,2S)-enantiomer)}.14
31.3, 34.3, 37.0, 37.2, 40.2, 119.9, 127.7, 132.0, 137.8,
141.7, 159.3, 197.5; nmax (KBr): 2954, 1649, 1618,
1459 cmK1. (1k) Mp 190–192 8C. 1H NMR (400 MHz,
CDCl3): 1.22 (s, 18H, 2tBu), 1.57 (s, 4H, adamantanyl H),
1.84 (m, 10H, adamantanyl H), 2.08–2.16 (m, 16H,
adamantanyl H), 4.72 (s, 2H, CH–CH), 6.97 (s, 2H,
aromatic H), 7.18 (m, 10H, aromatic H), 7.26 (d, 1.2 Hz,
2H, aromatic H), 8.40 (s, 2H, 2CH]N), 13.52 (s, 2H,
2ArOH); 13C NMR (100 MHz, CDCl3): 29.1, 31.4, 34.1,
37.2, 40.2, 80.1, 117.9, 126.3, 127.1, 127.3, 128.0, 128.2,
136.6, 139.8, 140.0, 158.2, 167.4; nmax (KBr): 1626 cmK1
(CH]N); [a]2D2ZC75.0 (cZ1.2, CH2Cl2); HRMS (ESI):
Calcd for C56H68N2O2 801.5354 (MCH), found 801.5374
(MCH).
4.2.7.
(1R,2R)-N,N0-Bis(50-methylsalicylidene)-1,2-
1
diphenyl-ethylenediimine (1g). Mp 55–56 8C. H NMR
(400 MHz, CDCl3): 2.21 (s, 6H, 2Me), 4.69 (s, 2H, CH–
CH), 6.86 (m, 2H, aromatic H), 6.92 (m, 2H, aromatic H),
7.06–7.09 (m, 2H, aromatic H), 7.16–7.21 (m, 10H,
aromatic H), 8.26 (s, 2H, 2CH]N), 13.07 (s, 2H,
2ArOH); [a]2D2ZK13.0 (cZ1.61, CH2Cl2); HRMS (ESI):
Calcd for C30H28N2O2 449.2224, found 449.2222 (MCH).
4.2.12. (1R,2R)-N,N0-Bis(50-phenylsalicylidene)-1,2-
diphenyl-ethylenediimine (1l). Mp 188–190 8C. H NMR
1
(400 MHz, CDCl3): 4.79 (s, 2H, CH–CH), 7.04 (d, JZ
8.8 Hz, 2H, aromatic H), 7.20–7.24 (m, 10H, aromatic H),
7.29 (d, JZ7.6 Hz, 2H, aromatic H), 7.38 (t, JZ7.6 Hz, 6H,
aromatic H), 7.45 (d, JZ7.6 Hz, 4H, aromatic H), 7.51 (dd,
JZ8.8 Hz, 0.8 Hz, 2H, aromatic H), 8.38 (s, 2H, 2CH]N),
13.38 (s, 2H, 2ArOH); 13C NMR (100 MHz, CDCl3): 80.2,
117.4, 118.6, 126.5, 126.8, 127.7, 127.8, 128.4, 128.8,
130.1, 131.4, 132.0, 139.3, 140.1, 160.4, 166.3; [a]2D2Z
C64.8 (cZ1.1, CH2Cl2); HRMS (ESI): Calcd for
C40H32N2O2 573.2537, found 573.2544 (MCH).
4.2.8. (1R,2R)-N,N0-Bis(50-tert-butylsalicylidene)-1,2-
diphenyl-ethylenediimine (1h). Mp 188–190 8C. 1H
NMR (400 MHz, CDCl3): 1.23 (s, 18H, 2tBu), 4.72 (s,
2H, CH–CH), 6.89 (d, JZ8.8 Hz, 2H, aromatic H), 7.12 (d,
JZ0.8 Hz, 2H, aromatic H), 7.15–7.19 (m, 10H, aromatic
H), 7.31 (dd, JZ8.8 Hz, 1.2 Hz, 2H, aromatic H), 8.34 (s,
2H, 2CH]N), 13.12 (s, 2H, 2ArOH); 13C NMR (100 MHz,
CDCl3): 31.3, 33.9, 80.2, 116.3, 117.9, 127.5, 127.9, 128.2,
128.3, 129.9, 139.6, 141.4, 158.6, 166.6; [a]2D2ZC8.3 (cZ
1.32, CH2Cl2); HRMS (ESI): Calcd for C36H40N2O2
533.3163, found 533.3173 (MCH).
4.2.13. 5,5-Methylene-di[(1R,2R)-N-(30-tert-butylsalicyli-
dine)-N0-(30,50-di-tert-butylsalicylidene)-1,2-diphenyl-
ethylene-diimine] (1m). The precursor 5,5-methylene-
bis(3-tert-butylsacylaldehyde) was prepared according to
the literature procedure.25 Mp 98–100 8C, (lit. mp 99–
100 8C).25 1H NMR (400 MHz, CDCl3): 1.41 (d, JZ2.0 Hz,
18H, 2tBu), 3.94 (s, 2H, CH2), 7.15 (d, JZ2.4 Hz, 2H,
aromatic H), 7.37 (d, JZ2.0 Hz, 2H, aromatic H), 9.81(d,
JZ3.6 Hz, 2H, 2CHO), 11.71 (d, JZ2.4 Hz, 2H, 2ArOH);
13C NMR (100 MHz, CDCl3): 29.1, 34.8, 40.0, 120.4,
131.1, 131.2, 134.9, 138.5, 159.8, 197.0. (1m) Mp 72–
4.2.9. (1R,2R)-N,N0-Bis(30-tert-butyl-50-methylsalicyli-
dene)-1,2-diphenylethylenediimine (1i). Mp 69–71 8C.
1H NMR (400 MHz, CDCl3): 1.41 (s, 18H, 2tBu), 2.18 (s,
6H, 2Me), 4.68 (s, 2H, CH–CH), 6.77 (d, JZ1.6 Hz, 2H,
aromatic H), 7.05 (d, JZ1.6 Hz, 2H, aromatic H), 7.17–7.21
(m, 10H, aromatic H), 8.30 (s, 2H, 2CH]N), 13.50 (s, 2H,
2ArOH); 13C NMR (100 MHz, CDCl3): 20.6, 29.3, 34.7,
80.2, 118.2, 126.5, 127.4, 128.0, 128.3, 130.0, 130.6, 136.7,
140.0, 157.9, 166.9; [a]2D2ZC140.4 (cZ0.99, CH2Cl2).
1
74 8C. H NMR (600 MHz, CDCl3): 1.34 (s, 36H, 4tBu),
1.48 (s, 18H, 2tBu), 2.10 (s, 2H, CH2), 4.86 (s, 4H, 2CH–
CH), 7.07 (s, 4H, aromatic H), 7.14–7.20 (m, 20H, aromatic
H), 7.29 (s, 4H, aromatic H), 9.76 (s, 4H, 4CH]N), 11.63
(s, 4H, 4ArOH); 13C NMR (100 MHz, CDCl3): 29.2, 29.3,
29.4, 31.4, 34.8, 34.9, 35.0, 40.0, 40.1, 80.0, 80.1, 117.8,
120.5, 126.3, 128.0, 128.27, 128.31, 129.8, 130.3, 131.1,
131.2, 134.9, 135.0, 138.6, 139.7, 157.9, 159.8, 166.7,
167.2, 197.0, 197.2; nmax (KBr): 3450, 1650 (m, CH]N)
cmK1; [a]2D2ZK24.6 (cZ1.26, CH2Cl2); HRMS (ESI):
Calcd for C81H96N4O4 1189.7504, found 1189.7503
(MCH).
4.2.10. (1R,2R)-N,N0-Bis(30,50-di-tert-butylsalicylidene)-
1,2-diphenylethylenediimine (1j). Mp 195–197 8C. 1H
NMR (400 MHz, CDCl3): 1.22 (d, JZ1.6 Hz, 18H,
2C(CH3)3), 1.42 (d, JZ2.0 Hz, 18H, 2C(CH3)3), 4.73 (d,
JZ1.6 Hz, 2H, CH–CH), 6.98 (m, 2H, aromatic H), 7.16–
7.20 (m, 10H, aromatic H), 7.31 (d, JZ2.4 Hz, 2H, aromatic
H), 8.40 (d, JZ1.2 Hz, 2H, 2CH]N), 13.60 (d, JZ2.0 Hz,
2H, exchangeable with D2O); 13C NMR (100 MHz, CDCl3):
29.4, 31.4, 34.0, 35.0, 80.1, 117.8, 126.3, 127.1, 127.4,
128.0, 128.2, 136.3, 139.8, 140.0, 157.9, 167.2; [a]2D2Z
K33.3 (cZ0.6, CHCl3) [lit. [a]2D0ZC32.4 (cZ0.25, CHCl3
for (1S,2S)-1j)].14a
Jacobsen’s ligands (1S,2S)-2a-g were synthesized according
to the literature procedure.26
4.2.11. (1R,2R)-N,N0-Bis(30-adamantyl-50-tert-butyl-
salicylidene)-1,2-diphenylethylenediimine (1k). The pre-
cursor 3-adamantyl-5-tert-butylsalicylaldehyde was synthe-
sized similarly to the literature procedure.15a Mp 128–130 8C.
1H NMR (400 MHz, CDCl3): 1.33 (s, 9H, tBu), 1.79 (s, 6H,
adamantanyl H), 2.09–2.14 (m, 9H, adamantanyl H), 7.33
(d, JZ1.6 Hz, 1H, aromatic H), 7.53 (s, 1H, aromatic H),
9.86 (s, 1H, CHO); 13C NMR (100 MHz, CDCl3): 28.9,
4.2.14. (1S,2S)-N,N0-Bis(30,50-di-tert-butylsalicylidene)-
cyclohexane-1,2-diimine (2a). Mp 206–207 8C, (lit. 200–
203 8C).26 1H NMR (400 MHz, CDCl3): 1.23 (s, 18H,
2tBu), 1.41 (s, 18H, 2tBu), 1.48 (m, 2H, cyclic H), 1.72–
1.96 (m, 6H, cyclic H), 3.30–3.33 (m, 2H, CH–CH), 6.98 (d,
JZ2.4 Hz, 2H, aromatic H), 7.30 (d, JZ2.0 Hz, 2H,
aromatic H), 8.30 (s, 2H, 2CH]N), 13.72 (s, 2H,
2ArOH); 13C NMR (100 MHz, CDCl3): 24.3, 29.4, 31.4,