) 15.5, 9.2 Hz), 7.15-7.49 (5 H, m); 13C NMR (67.8 MHz, CDCl3)
δ 11.7, 36.9, 41.1, 93.9, 126.9, 128.7, 132.6, 169.3. HRMS calcd
for C12H15NO 189.1154, found 189.1152. The second fraction
gave a mixture of 15 and 16 (84.6 mg, 48%) in a ratio of ca. 3:1:
IR (CHCl3) ν 1640 cm-1; 1H NMR (500 MHz, C6D6) δ 0.85 (1/4 ×
3 H, t, J ) 7.1 Hz, for 16), 0.92 (3/4 × 3 H, d, J ) 6.8 Hz, for
15), 0.96 (3/4 × 3 H, t, J ) 7.3 Hz, for 15), 2.48 (1/4 × 2 H, t, J
) 5.9 Hz, for 16) 2.75 (3/4 H, dq, J ) 13.8, 6.9 Hz, for 15), 2.86
(1/4 × 2 H, t, J ) 9.2 Hz, for 16), 3.20 (1/4 × 2 H, q J ) 7.1 Hz,
for 16), 3.37 (3/4 H, d, J ) 19.0 Hz, for 15); 3.52 (3/4 H, d, J )
19.0 Hz, for 15), 3.66 (1/4 × 2 H, s, for 16), 3.84 (3/4 H, dq, J )
13.9, 7.0 Hz, for 15), 3.90 (3/4 H, q, J ) 6.7 Hz, for 15), 6.71-
7.32 (3/4 × 4 H + 1/4 × 4 H, m, for 15 and 16). HRMS calcd for
127.1, 129.2, 129.4, 130.6, 130.8, 136.7, 137.5, 139.5, 140.4, 161.7,
161.9. 1H and 13C NMR spectra of 21a showed it to be a mixture
of rotamers. HRMS calcd for C12H15NO 189.1154, found 189.1152.
Radical Cyclization of 14b at Room Temperature. To a
solution of 14b (91 mg, 0.323 mmol) and V-70 (50.0 mg, 0.161
mmol) in toluene (20 mL) was added Bu3SnH (155 mg, 0.532
mmol) at room temperature, and the mixture was stirred at the
same temperature for 10 h. After workup, the crude material
was chromatographed on silica gel (hexane/AcOEt, 4:1 f 3:1).
The first fraction gave a mixture of 14b and 23b (31.1 mg) as a
colorless oil. The second fraction gave 21b (8.6 mg, 13%) as a
colorless oil.
N-[2-(6-Bromobenzo[1,3]dioxol-5-yl)ethyl]-N-(cyclopent-
1-enyl)acrylamide (29). A mixture of 2-(6-bromo-1,3-benzo-
dioxol-5-yl)ethylamine (491 mg, 2.01 mmol) and cyclopentanone
(200 mg, 2.38 mmol) in benzene (10 mL) was heated under reflux
with azeotropic removal of water for 2 h. After cooling, Et3N
(407 mg, 4.02 mmol) and acryloyl chloride (267 mg, 2.95 mmol)
were added to the reaction mixture, and the mixture was stirred
at room temperature for 20 min. The reaction mixture was
diluted with water and extracted with AcOEt. The organic layer
was washed with brine, dried (MgSO4), and concentrated. The
residue was chromatographed on silica gel (hexane/AcOEt, 5:1)
to give 29 (467 mg, 64%) as colorless crystals, mp 96.5-97.5 °C
(hexane); IR (CHCl3) ν 1645 cm-1; 1H NMR (270 MHz, CDCl3) δ
1.98 (2 H, quint., J ) 7.6 Hz), 2.37-2.42 (4 H, m), 2.90-2.95 (2
H, m), 3.62-3.68 (2 H, m), 5.43 (1 H, s), 5.60 (1 H, dd, J ) 9.9,
2.3 Hz), 5.95 (2 H, s), 6.36 (1 H, dd, J ) 16.8, 2.3 Hz), 6.51 (1 H,
dd, J ) 16.8, 9.9 Hz), 6.78 (1 H, s), 6.97 (1 H, s); 13C NMR (67.8
MHz, CDCl3) δ 22.4, 30.4, 32.8, 34.4, 45.9, 101.6, 110.7, 112.6,
114.4, 126.9, 129.0, 131.3, 142.2, 147.0, 147.4, 165.5. Anal. Calcd
for C17H18BrNO3: C, 56.06; H, 4.98; N, 3.85. Found: C, 56.28;
H, 5.00; N, 3.79.
C12H15NO 189.1154, found 189.1155. Anal. Calcd for C12H15
-
NO: C, 76.16; H, 7.99; N, 7.40. Found: C, 75.75; H, 7.96; N,
7.36.
3-Formyl-2,3,4,5-tetrahydro-1H-3-benzazepine(18a),2-Form-
yl-1,2,3,4-tetrahydro-1-methylisoquinoline (19a), and N-
Ethenyl-N-(2-phenylethyl)formamide (20a). Following the
general procedure, a boiling solution of 13a (100 mg, 0.394 mmol)
in toluene (20 mL) was treated with Bu3SnH (172 mg, 0.590
mmol) and ACN (19.2 mg, 0.0787 mmol) in toluene (20 mL).
After workup, the crude material was chromatographed on silica
gel (hexane/AcOEt, 6:1 f 2:1 f 3:2). The first fraction gave 20a
(11.1 mg, 16%) as a colorless oil: IR (CHCl3) ν 1690, 1635 cm-1
;
1H NMR (270 MHz, CDCl3) δ 2.86 (3/4 × 2 H, t, J ) 7.6 Hz),
2.92 (1/4 × 2 H, t, J ) 6.9 Hz), 3.69 (1/4 × 2 H, t, J ) 6.9 Hz),
3.79 (3/4 × 2 H, t, J ) 7.6 Hz) 4.47 (1 H, dd, J ) 9.2, 1.5 Hz),
4.64 (3/4 H, dd, J ) 16.2, 1.5 Hz), 4.67 (1/4 H, dd J ) 16.2, 1.5
Hz), 6.57 (3/4 H, dd, J ) 16.2, 9.2 Hz), 7.12-7.37 [(1/4 + 5 H),
m], 7.74 (1/4 H, s), 8.29 (3/4 H, s); 13C NMR (67.8 MHz, CDCl3)
δ 32.5, 33.6, 41.8, 47.0, 93.8, 95.3, 126.6, 127.0, 128.6, 161.1,
162.3. 1H and 13C NMR spectra of 20a showd it to be a mixture
of rotamers. HRMS calcd for C11H13NO 175.0997, found 175.0991.
The second fraction gave a mixture of 18a and 19a (29.0 mg,
42%) in a ratio of 97:3: IR (CHCl3) ν 1670, 1660 cm-1; 1H NMR
(500 MHz, C6D6) δ 0.94 (3/100 × 3 H, d, J ) 6.8 Hz, for 19a),
1.97 (97/100 × 2 H, t, J ) 5.1 Hz, for 18a), 2.13 (97/100 × 2 H,
t, J ) 5.1 Hz, for 18a), 2.33 (97/100 × 2 H, t, J ) 5.0 Hz, for
18a), 3.14 (97/100 × 2 H, t, J ) 5.0 Hz, for 18a), 4.11 (3/100 H,
dd, J ) 13.2, 6.5 Hz, for 19a), 5.24 (3/100 H, q, J ) 6.8 Hz, for
19a), 6.43-6.60 (97/100 × 2 H + 3/100 × 2 H, m, for 18a and
19a), 6.65-6.70 (97/100 × 2 H + 3/100 × 2 H, m, for 18a and
19a), 7.52 (97/100 H, s, for 18a), 7.72 (3/100 H, s, for 19a); 13C
NMR (125 MHz, C6D6 for 18a) δ 37.7, 39.1, 42.6, 48.5, 127.0,
(3aR*,14bS*)-1,2,3,8,9,14b-Hexahydro-4H-cyclopenta[a]-
[1,3]dioxolo[4,5-h]pyrrolo[2,1-b][3]benzazepin-6(5H)-one
(30). Following the general procedure, a boiling solution of 29
(200 mg, 0.549 mmol) in toluene (50 mL) was treated with Bu3-
SnH (238 mg, 0.818 mmol) and ACN (13.4 mg, 0.0548 mmol) in
toluene (50 mL). The solvent was evaporated off and the residue
was taken up in CH3CN. This mixture was washed with hexane
and concentrated. The residue was chromatographed on silica
gel (hexane/AcOEt, 1:2) to give 30 (50.2 mg, 32%) as colorless
crystals. A sample was recrystallized from hexane/AcOEt for
X-ray crystallographic analysis (see Supporting Information):
127.3, 130.0, 130.2, 140.8, 141.7, 161.5. HRMS calcd for C11H13
NO 175.0997, found 175.0996.
-
mp 176-179 °C; IR (CHCl3) ν 1670 cm-1 1H NMR (270 MHz,
;
3-Formyl-2,3,4,5-tetrahydro-2-methyl-1H-3-benza-
zepine (21a), 2-Formyl-1,2,3,4-tetrahydro-1,1-dimethyliso-
quinoline (22), and N-(1-Methylethenyl)-N-(2-phenylethyl)-
formamide (23a). Following the general procedure, a boiling
solution of 14a (100 mg, 0.373 mmol) in toluene (20 mL) was
treated with Bu3SnH (163 mg, 0.559 mmol) and ACN (18.2 mg,
0.0746 mmol) in toluene (20 mL). After workup, the crude
material was chromatographed on silica gel (hexane/AcOEt, 6:1
f 3:2). The first fraction gave 23a (5.5 mg, 8%) as a colorless
CDCl3) δ 1.50-2.29 (10 H, m), 2.55-2.66 (1 H, m), 2.98 (1 H,
dd, J ) 10.9, 8.6 Hz), 3.07-3.24 (2 H, m), 3.96-4.09 (1 H, m),
5.89 (1 H, d, J ) 1.7 Hz), 5.90 (1 H, d, J ) 1.7 Hz), 6.59 (1 H, s),
6.62 (1 H, s); 13C NMR (67.8 MHz, CDCl3) δ 24.0, 29.7, 30.2,
33.7, 35.4, 38.5, 38.6, 57.8, 69.6, 100.9, 110.7, 111.0, 129.8, 133.0,
146.2, 146.5, 175.5. Anal. Calcd for C17H19NO3: C, 71.56; H, 6.71;
N, 4.91. Found: C, 71.37; H, 6.62; N, 4.89. Several byproducts
were also formed, but their structures were unknown at the
moment.
oil: IR (CHCl3) ν 1670, 1645, 1630 cm-1 1H NMR (270 MHz,
;
CDCl3) δ 1.99 (3 H, s), 2.83 (2 H, t like, J ) 7.9 Hz), 3.79 (2 H,
t like, J ) 7.9 Hz), 4.61 (1 H, s), 4.62 (1 H, s), 7.19-7.32 (5 H,
m), 8.42 (1 H, s); 13C NMR (67.8 MHz, CDCl3) δ 20.1, 33.6, 43.1,
102.8, 126.5, 128.5, 128.8, 138.5, 141.4, 160.8. HRMS calcd for
C12H15NO 189.1154, found 189.1153. The second fraction gave
a mixture of 21a and 22 (50.8 mg, 72%) in a ratio of 93:7: IR
(CHCl3) ν 1660 cm-1; 1H NMR (270 MHz, CDCl3) δ 0.93 (93/200
× 3 H, d, J ) 6.9, for 21a), 1.04 (93/200 × 3 H, d, J ) 6.9 Hz, for
21a), 1.75 (7/100 × 6 H, s, for 22), 2.72-3.00 (93/100 × 3 H +
93/200 H, m, for 21a), 3.11-3.21 (93/100 H, m, for 21a), 3.25-
3.35 (93/200 H, m, for 21a), 3.54-3.62 (93/200 H, m, for 21a),
3.84 (7/100 × 2 H, t, J ) 5.8 Hz, for 22), 3.97-4.03 (93/200 H,
m, for 21a), 4.50-4.57 (93/200 H, m, for 21a), 5.00-5.06 (93/
200 H, m, for 21a), 7.06-7.24 (93/100 × 4 H + 7/200 × 4 H, m,
for 21a and 22), 8.08 (93/200 H, s, for 21a), 8.17 (93/200 H, s,
for 21a), 8.63 (7/100 H, s, for 22); 13C NMR for 21a (67.8 MHz,
CDCl3) δ 15.5, 17.1, 36.9, 37.9, 41.6, 43.1, 44.2, 52.2, 126.7, 126.9,
Acknowledgment. This work was supported by a
Grant-in-Aid for Scientific Research from the Ministry
of Education, Culture, Sports, Science and Technology
of Japan.
Supporting Information Available: Experimental pro-
cedure for 7, 8, 9, 10, 11b-d, 12a-d, 13b-d, 14a-d, 18b-
d, 19c,d, 20b-d, 21b-d, and 23b,c; 1H and 13C NMR spectra
for 6, 9, 11c,d, 13c,d, 14b, 17, 18a,b, 18d, 19a, 19d, 20a-d,
21a-d, 22, and 23a-c (1H NMR spectrum only for 23b); and
X-ray crystallographic data for 30 in CIF format. This material
JO040264U
J. Org. Chem, Vol. 70, No. 5, 2005 1925