904 Bull. Chem. Soc. Jpn., 78, No. 5 (2005)
N,N-Dimethylchalcogenocarbamates
C9H19NOTe: C, 37.95; H, 6.72; N, 4.92%.
4b (R = benzyl): Yellow oil; MS (m=z) 293 (Mþ; 52%, 130Te),
91 (C7H7; bp); IR (neat) 3020, 2915, 1640, 1350, 1250, 1060, 880,
methylselenocarbamates 3 with Tin(IV) Chloride. A 15 mL
CH2Cl2, CHCl3, or C2H4Cl2 solution of Se-alkyl or Se-alkenyl
N,N-dimethylselenocarbamate 3 (0.25 mmol) was treated with
SnCl4 (35 mg, 0.5 mmol) at refluxing temperature for 0.5 h.
The reaction was then quenched with an excess amount of aque-
ous sodium hydrogen carbonate solution, and the mixture was ex-
tracted with chloroform. The organic layer was washed with wa-
ter, and dried over anhydrous Na2SO4 powder. After removing the
solvent in vacuo, the crude mixture was subjected to column chro-
matographic separation on silica gel to afford the corresponding
symmetrical diselenide 7 in high-to-moderate yields along with
the contamination of monoselenide 5b in the case of the reaction
starting from 3b.
700 cmꢄ1 1H NMR (CDCl3) ꢀ 2.81 (3H, br.s), 3.07 (3H, br.s),
;
4.03 (2H, s), 7.11–7.15 (1H, m), 7.21–7.25 (2H, m), 7.31–7.33
(2H, m); 13C NMR (CDCl3) ꢀ 15.7 (t), 35.9 (q), 38.2 (q), 126.1
(d), 128.4 (d), 141.6 (s), 157.0 (s). Found: C, 41.04; H, 4.37; N,
4.76%. Calcd for C10H13NOTe: C, 41.30; H, 4.51; N, 4.82%.
4c (R = allyl): Yellow oil; MS (m=z) 243 (Mþ; 42%, 130Te),
72 (C3H6NO; bp); IR (neat) 2990, 1630, 1345, 1240, 1060, 875
cmꢄ1 1H NMR (CDCl3) ꢀ 2.85 (3H, br.s), 3.03 (3H, br.s), 3.65
;
(2H, d, J ¼ 8:0 Hz), 4.86 (1H, br.d, J ¼ 10:0 Hz), 5.11 (1H,
br.d, J ¼ 17:0 Hz), 6.05 (1H, ddt, J ¼ 17:0, 10.0, 8.0 Hz). Found:
C, 37.12; H, 5.58; N, 7.14%. Calcd for C6H11NOTe: C, 37.51; H,
5.77; N, 7.29%.
7g (R = CH2CO2–l-menthyl): Pale yellow needles, mp 42.1–
43.9 ꢁC; MS (m=z) 552 (Mþ; 1%, 80Se), 276 (Mþ/2; 2%, 80Se), 69
(C5H9; bp, 80Se); IR (KBr) 2948, 1709, 1386, 1288, 1102, 990,
4d (R = methallyl): Yellow oil; MS (m=z) 257 (Mþ; 99%,
130Te), 255 (Mþ; bp, 128Te), 185 (C4H7Te; 27%, 130Te); IR (neat)
670 cmꢄ1 1H NMR (CDCl3) ꢀ 0.76–2.04 (36H, m), 3.73 (4H,
;
1
2929, 1651, 1356, 1245, 1084, 885, 666 cmꢄ1; H NMR (CDCl3)
br.s), 4.70 (2H, dt, J ¼ 10:9, 4.4 Hz); 13C NMR (CDCl3) ꢀ 16.2
(q), 20.8 (q), 21.9 (q), 23.2 (t), 26.0 (d), 29.9 (t), 31.3 (d), 34.1
(t), 40.6 (dd), 46.9 (d), 75.4 (br.s), 170.1 (s). Found: C, 52.20;
H, 7.71%. Calcd for C24H42O4Se2: C, 52.17; H, 7.66%.
ꢀ 1.78 (3H, s), 2.87 (3H, br.s), 3.05 (3H, br.s), 3.72 (2H, s), 4.72
(1H, br.s), 4.98 (1H, br.s). Found: C, 40.35; H, 6.23; N, 6.65%.
Calcd for C7H13NOTe: C, 40.78; H, 6.36; N, 6.79%.
4e (R = cyclohexyl): Yellow oil; MS (m=z) 285 (Mþ; 26%,
130Te), 72 (C3H6NO; bp); IR (neat) 2890, 2825, 1620, 1430,
7h (R = (Z)-CH=CHCO2CH3): Pale yellow needles, mp
ꢁ
71.0–72.0 C (dec.); MS (m=z) 330 (Mþ; 39%, 80Se), 165 (Mþ/
1
1335, 1240, 1060 cmꢄ1; H NMR (CDCl3) ꢀ 1.20–1.80 (6H, m),
2; 64%, 80Se), 163 (Mþ/2; bp, 78Se); IR (KBr) 1680, 1570,
1.80–2.40 (4H, m), 2.87 (3H, br.s), 3.40 (3H, br.s), 3.50–3.90
(1H, m). Found: C, 45.98; H, 7.17; N, 5.79%. Calcd for
C9H17NOTe: C, 46.16; H, 7.32; N, 5.98%.
1436, 1343, 1213, 1145, 1006, 922 cmꢄ1 1H NMR (CDCl3) ꢀ
;
3.79 (6H, s), 6.28 (2H, d, J ¼ 9:4 Hz), 8.06 (2H, d, J ¼ 9:4
Hz); 13C NMR (CDCl3) ꢀ 51.7 (q), 118.7 (d), 148.5 (d), 167.2
(s). Found: C, 29.71; H, 3.23%. Calcd for C8H10O4Se2: C,
29.29; H, 3.07%.
4h (R = (Z)-CH=CHCO2CH3): Colorless needles, mp
104.0–105.0 ꢁC; MS (m=z) 287 (Mþ; bp, 130Te), 215 (C4H5O2Te;
94%, 130Te); IR (KBr) 1690, 1630, 1560, 1320, 1205 cmꢄ1
;
Synthesis of Symmetrical Ditellurides 11 by Treating N,N-
Dimethyltellurocarbamates 4 with Tin(IV) Chloride. A 15
mL CH2Cl2 or CHCl3 solution of Te-alkyl or Te-alkenyl N,N-di-
methyltellurocarbamate 4 (0.25 mmol) was treated with SnCl4 (35
mg, 0.5 mmol) at refluxing temperature for 0.5 h. The reaction
was then quenched with an excess amount of aqueous sodium hy-
drogen carbonate solution, and the mixture was extracted with
CHCl3. The organic layer was washed with water and then with
brine, and dried over anhydrous Na2SO4 powder. After removing
the solvent in vacuo, the crude mixture was subjected to column
chromatographic separation on silica gel to afford the correspond-
ing symmetrical ditelluride 8 in high-to-moderate yields along
with the formation of a trace amount of monotelluride 6.
6h (R = ꢁ(Z)-CH=CHCO2CH3): Pale yellow plates, mp
138.5–139.5 C; MS (m=z) 300 (Mþ; 50%, 130Te), 215 (C4H5O2;
bp, 130Te); IR (KBr) 1680, 1540, 1400, 1315, 1200, 990, 800, 630
cmꢄ1; 1H NMR (CDCl3) ꢀ 3.80 (6H, s), 5.98 (2H, d, J ¼ 10:0 Hz),
8.53 (2H, d, J ¼ 10:0 Hz). Found: C, 32.11; H, 3.19%. Calcd for
C8H10O4Te: C, 32.27; H, 3.39%.
1H NMR (CDCl3) ꢀ 2.96 (3H, br.s), 3.09 (3H, br.s), 3.81 (3H,
br.s), 6.97 (1H, br.d, J ¼ 9:5 Hz), 8.94 (1H, br.d, J ¼ 9:5 Hz);
13C NMR (CDCl3) ꢀ 35.8 (q), 37.4 (q), 52.2 (q), 123.2 (d),
140.6 (d), 159.8 (s), 169.1 (s). Found: C, 29.30; H, 3.71; N,
4.91%. Calcd for C7H11NO3Te: C, 29.53; H, 3.89; N, 4.92%.
4i (R = (Z)-CH=CH–(p-CF3C6H4)): Colorless plates, mp
109.0–110.0 ꢁC; MS (m=z) 373 (Mþ; 27%, 130Te), 301
(C9H6F3Te; 21%, 130Te), 171 (C9H6F3; 38%), 151 (C9H5F2,
bp); IR (KBr) 1650, 1329, 1112, 1067, 853 cmꢄ1 1H NMR
;
(CDCl3) ꢀ 2.86 (3H, br.s), 3.08 (3H, br.s), 7.35 (2H, d, J ¼ 8:1
Hz), 7.42–7.50 (2H, m), 7.60 (2H, d, J ¼ 8:1 Hz); 13C NMR
(CDCl3) ꢀ 36.1 (q), 37.1 (q), 115.3 (d), 125.2 (dq, JC{F ¼ 4
Hz), 127.5 (d), 129.0 (q, JC{F ¼ 32 Hz), 135.7 (d), 142.5 (s),
155.3 (s). Found: C, 38.95; H, 3.18; N, 3.71%. Calcd for
C12H12F3NOTe: C, 38.87; H, 3.26; N, 3.78%.
4j (R = (Z)-CH=CH–(2,6-Cl2C6H3)): Yellow plates, mp
91.5–92.0 ꢁC (dec.); MS (m=z) 373 (Mþ; 5%, 130Te, 35Cl), 171
(C8H5Cl2; bp, 35Cl); IR (KBr) 1655, 1060 cmꢄ1 1H NMR
;
(CDCl3) ꢀ 2.79 (3H, br.s), 3.05 (3H, br.s), 7.16 (1H, t, J ¼ 8:0
Hz), 7.25 (1H, d, J ¼ 10:5 Hz), 7.31 (2H, d, J ¼ 8:0 Hz), 7.58
(1H, d, J ¼ 10:5 Hz); 13C NMR (CDCl3) ꢀ 35.9 (q), 37.5 (q),
120.0 (d), 128.0 (br.d), 129.1 (br.d), 133.1 (d), 134.0 (s), 137.5
(s), 155.8 (s). Found: C, 35.71; H, 2.96; N, 3.77%. Calcd for
C11H11Cl2NOTe: C, 35.54; H, 2.98; N, 3.77%.
4kꢁ (R = (Z)-C6H5C=CHCOCH3): Yellow solid, mp 67.0–
67.5 C; MS (m=z) 347 (Mþ; 3%, 130Te), 275 (Mþ ꢄ Me2NCO;
55%, 130Te), 43 (bp); IR (neat) 2924, 1638, 1608, 1522, 1483,
1360, 1310, 1222, 1182, 1090, 981, 823, 762, 703 cmꢄ1; 1H NMR
(CDCl3) ꢀ 2.33 (3H, s), 2.57 (3H, s), 2.77 (3H, s), 7.36–7.65 (6H,
m). Found: C, 44.97; H, 4.38; N, 3.77%. Calcd for C13H15NOTe:
C, 45.28; H, 4.38; N, 4.06%.
8i (R = (Z)-CH=CHCO2CH3): Yellow plates; MS (m=z) 430
(Mþ; 10%, 130Te), 215 (Mþ/2; bp, 130Te); IR (KBr) 1670, 1561,
1432, 1334, 1203, 1003, 803 cmꢄ1; 1H NMR (CDCl3) ꢀ 3.81 (6H,
s), 6.65 (2H, d, J ¼ 10:0 Hz), 8.99 (2H, d, J ¼ 10:0 Hz). Found:
C, 23.04; H, 2.53%. Calcd for C8H10O4Te2: C, 22.59; H, 2.37%.
8j (R = (Z)-CH=CH–(2,6-Cl2C6H3)): Red plates, mp 111.5–
112.5 ꢁC (dec.); MS (m=z) 606 (Mþ; 8%, 130Te, 35Cl), 303 (Mþ/
2; 4%, 130Te, 35Cl), 173 (C8H5Cl2; bp); IR (KBr) 2925, 1556,
1
1425, 1297, 1193, 1085, 790, 776, 712 cmꢄ1; H NMR (CDCl3)
ꢀ 6.87 (2H, d, J ¼ 10:5 Hz), 7.20 (2H, t, J ¼ 8:0 Hz), 7.33 (4H,
d, J ¼ 8:0 Hz), 7.88 (2H, d, J ¼ 10:5 Hz); 13C NMR (CDCl3) ꢀ
109.4 (d), 128.2 (br.d), 129.4 (br.d), 134.2 (br.s), 135.5 (d),
136.2 (br.s). Found: C, 32.01; H, 1.74%. Calcd for C16H10Cl4Te2:
C, 32.07; H, 1.68%.
Synthesis of Symmetrical Diselenides 7 by Treating N,N-Di-