Rearrangement of N-Aryl-2-Vinylaziridines
FULL PAPER
methyl-1,3-pentadiene (0.38 mL, 3.28 mmol). The resulting red solution
was first stirred at 658C in a preheated oil bath for 11 h and for 12 h
after adding silica (400 mg). The rest of the procedure was identical to
that described for 2 (7, 58%). The reaction was repeated by increasing
the temperature to reflux after the arylazide had been completely con-
sumed. Compound 7 was recovered in 35% yield after 20 h and column
purification (silica gel, n-hexane/ethyl acetate 9.5:0.5!8:2). 1H NMR
(300 MHz, CDCl3): d=7.95 (d, J=2.4 Hz, 1H; ArH), 7.91 (dd, J=8.7,
2.4 Hz, 1H; ArH), 6.49 (d, J=8.7 Hz, 1H; ArH), 5.54 (dd, J=6.4, 1.5 Hz,
(EI): m/z: 218 [M+]; elemental analysis calcd (%) for C12H14N2O2
(218.26): C 66.04, H 6.47, N 12.84; found: C 66.18, H 6.69, N 12.66.
Compounds cis- and trans-10: 1H NMR (300 MHz, CDCl3): cis-10: d=
8.11 (d, J=8.8 Hz, 2H; ArH), 6.92 (d, J=8.8 Hz, 2H; ArH), 5.93 (m,
ꢀ
ꢀ
1H; CH=CH CH
G
ꢀ
CH
G
G
ꢀ
3H; CH CH
N
ACHUTGTNERN(NUG CH3) CHACHTUNGTRENNUNG(CH3)
N); 13C NMR (75 MHz, CDCl3): cis-10: d=157.6 (C), 142.6 (C), 131.6
(CH), 127.8 (CH), 125.4 (CH), 120.9 (CH), 48.4 (CH(CH3)), 42.7 (CH-
(CH3)), 18.4 (CH3), 17.1 ppm (CH3); 1H NMR (300 MHz, CDCl3): trans-
10: d=8.11 (d, J=8.8 Hz, 2H; ArH), 6.90 (d, J=8.8 Hz, 2H; ArH), 5.79
1H; CH=C
CH(CH3)), 3.51 (d, J=15.3 Hz, 1H; CH2), 1.78 (s, 3H; CH=C
1.45 ppm (d, J=6.4 Hz, 3H; CH
(CH3)); 13C NMR (75 MHz, CDCl3): d=
ACHTUNGTRENNUNG
AHCTUNGTRENNUNG
A
ACHTUNGTRENNUNG
AHCTUNGTRENNUNG
ꢀ
ꢀ
(m, 1H; CH=CH CHACTHNUTRGNE(UNG CH3)), 4.69 (m, 1H; N CH=CH), 3.03 (m, 1H;
131.4 (CH), 124.2 (CH), 123.0 (CH), 117.3 (CH), 48.8 (CH2), 34.5 (CH),
23.0 (CH3), 19.3 ppm (CH3); MS (ESI): m/z: 216 [M+ꢀ2H], 201 [M+
ꢀ2HꢀCH3], 155 [M+ꢀ2HꢀCH3ꢀNO2]; elemental analysis calcd (%) for
C12H14N2O2 (218.26): C 66.04, H 6.47, N 12.84; found: C 66.11, H 6.78, N
12.53.
ꢀ
ꢀ
ꢀ
ꢀ
CH CH
G
E
E
ACHTUNGTRENNUNG
ꢀ
ꢀ
(m, 3H; CH CH
G
G
(CH3) N); 13C NMR (75 MHz, CDCl3): trans-10: d=157.4 (C), 142.6 (C),
ꢀ
130.8 (CH), 126.7 (CH), 125.4 (CH), 120.9 (CH), 43.7 (CHACTHNUTRGNE(UNG CH3)), 43.1
(CHACHTUNGTRNEUN(G CH3)), 17.4 (CH3), 13.8 ppm (CH3); MS (EI): cis- + trans-10: m/z:
218 [M+]; elemental analysis calcd (%) for C12H14N2O2 (218.26): C 66.04,
cis- and trans-2-Methyl-N-(4-nitrophenyl)-3-propenyl aziridine (8):
ACHTUNGTRENNUNG
(tpp)] (10.0 mg, 1.35ꢃ10ꢀ2 mmol) and 4-nitrophenyl azide
H 6.47, N 12.84; found: C 66.21, H 6.42, N 12.86.
[Ru(CO)
(106.1 mg, 6.47ꢃ10ꢀ1 mmol) were added to
a
dry benzene solution
cis-2,3-Dihydro-1-(4-nitrophenyl)-2,3-diphenyl-1H-pyrrole
[Ru(CO)
(tpp)] (10.5 mg, 1.42ꢃ10ꢀ2 mmol) and 4-nitrophenyl azide
(107 mg, 6.53ꢃ10ꢀ2 mmol) were added to
dry benzene solution
(12):
(30.0 mL) of 2,4-hexadiene (0.50 mL, 3.90 mmol). The resulting red solu-
tion was stirred at 658C in a preheated oil bath. The consumption of the
arylazide was monitored by TLC, until the corresponding spot was no
longer observable, and then by IR spectroscopy (40 h). The reaction was
considered to be finished when the absorbance of the azide band at
2121 cmꢀ1 in the IR spectrum of the solution, measured with a 0.5 mm
thick cell, was at or below 0.03. The obtained red solution was evaporat-
ed to dryness and the residue was purified by flash chromatography on
deactivated silica gel with the use of Et3N in n-hexane (10%) during the
packing of the column (n-hexane/ethyl acetate 10:0!9:1) to give com-
pound 8 (53%, trans-8/cis-8 2:1). 1H NMR (300 MHz, CDCl3): trans-8:
d=8.09 (d, J=8.8 Hz, 2H; ArH), 7.00 (d, J=8.8 Hz, 2H; ArH), 5.93 (m,
ꢀ
AHCTUNGTRENNUNG
a
(30.0 mL) of trans,trans-1,4-diphenyl-1,3-butadiene (730 mg, 3.54 mmol).
The resulting red solution was first stirred at 658C in a preheated oil
bath for 4 h and then for 8 h more after adding silica (400 mg). The rest
of the procedure was identical to that described for 2 (12, 50%). The re-
action was repeated by increasing the temperature to reflux after 4 h
when the arylazide had been completely consumed. Compound 12 was
recovered after 4h more (70%). 1H NMR (300 MHz, C6D6): d=7.94 (d,
J=9.2 Hz, 2H; ArH), 7.03–6.63 (m, 10H; ArH), 6.55 (d, J=4.2 Hz, 1H;
N-CH=CH), 6.21 (d, 2H, J=9.2 Hz; ArH), 5.00 (dd, J=4.2, 2.2 Hz, 1H;
ꢀ
ꢀ
N CH=CH), 4.87 (d, J=10.8 Hz, 1H; N-CH(Ph) CH(Ph)), 4.52 ppm
(dd, J=10.8, 2.2 Hz, 1H; N CH(Ph) CH(Ph)); 13C NMR (75 MHz,
C6D6): d=145.27 (C), 138.2 (C), 136.7 (C), 132.1 (C), 129.7 (CH), 127.5
(CH), 127.1 (CH), 126.0 (CH), 112.5 (CH), 110.4 (C), 68.9 (CH),
54.8 ppm (CH); MS (ESI): m/z: 342 [M+], 310 [M+ꢀ2O]; elemental
analysis calcd (%) for C22H18N2O2 (342.40): C 77.17, H 5.31, N 8.18;
found: C 77.51, H 5.20, N 7.93.
ꢀ
ꢀ
1H; CH=CH
ACHTUNGTRENNUNG(CH3)), 5.45 (m, 1H; CH=CHCAHTUNGTRENNNUG
ꢀ
G
ꢀ
ACHTUNGTRENNUNG(CH3))), 1.36 ppm (m, 3H; N CHCAHTUNGTRENNNUG
d=161.9 (C), 142.9 (C), 131.1 (CH), 126.1 (CH), 125.6 (CH), 120.4 (CH),
46.4 (CH), 41.9 (CH), 18.4 (CH3), 14.2 ppm (CH3); cis-8: d=8.11 (d, J=
8.8 Hz, 2H; ArH), 7.02 (d, J=8.8 Hz, 2H; ArH), 5.85 (m, 1H; CH=CH-
ꢀ
ACHTUNGTRENNUNG(CH3)), 5.35 (m, 1H; CH=CHACHUTNRTGEG(NNNU CH3)), 2.99 (m, 1H; N CHACTHUNGTRENNUNG
3,4-Dimethoxy-1-(4-nitrophenyl)-1H-pyrrole
(14):
[Ru(CO)ACHTUNGTRENNUNG(tpp)]
(9.5 mg, 1.28ꢃ10ꢀ2 mmol) and 4-nitrophenyl azide (102.5 mg, 6.25ꢃ
10ꢀ1 mmol) were added to a dry benzene solution (30.0 mL) of 2,3-dime-
thoxy-1,3-butadiene (0.40 mL, 3.13 mmol). The resulting dark solution
was stirred at 658C in a preheated oil bath. The consumption of the aryl-
ꢀ
(m, 1H; N CH
1.38 ppm (m, 3H; N CHAHCTUNGTRENNUNG
ACHTUNGTRENNUNG(CH=CHACHTNURTGENG(UNN CH3))), 1.82 (m, 3H; (CH=CHACTHUNGTRENNUGN
ꢀ
(C), 143.0 (C), 130.2 (CH), 126.1 (CH), 125.6 (CH), 120.6 (CH), 42.3
(CH), 41.8 (CH), 14.6 (CH3), 14.2 ppm (CH3); MS (EI): cis- + trans-8:
m/z: 218 [M+]; elemental analysis calcd (%) for C12H14N2O2 (218.26): C
66.04, H 6.47, N 12.84; found: C 66.19, H 6.61, N 12.69.
AHCTUNGERTGaNNUN zide was monitored by TLC, until its spot was no longer observable, and
then by IR spectroscopy (36 h). After chromatographic purification, pure
pyrrole 14 was obtained as an orange solid in 60% yield. 1H NMR
(300 MHz, CDCl3): d=8.25 (d, J=9.2 Hz, 2H; ArH), 7.32 (d, J=9.2 Hz,
2H; ArH), 6.63 (s, 2H; CH), 3.83 ppm (s, 6H; OCH3); 13C NMR
(75 MHz, CDCl3): d=145.8 (C), 143.4 (C), 142.8 (C), 126.1 (CH), 116.8
(CH), 99.6 (CH), 58.7 ppm (OCH3); MS (ESI): m/z: 248 [M+], 233 [M+
ꢀCH3]; elemental analysis calcd (%) for C12H12N2O4 (248.24): C 58.06, H
4.87, N 11.28; found: C 58.10, H 4.94, N 11.44.
(Z)-2,5-Dihydro-2,5-dimethyl-7-nitro-1H-benzo[b]azepine (9) and cis-
and trans-2,3-dihydro-2,3-dimethyl-1-(4-nitrophenyl)-1H-pyrrole (10):
The product
8 was synthesized as described above and then silica
(400 mg) was added to the reaction mixture before the isolation of 8. N-
aryl-2-vinylaziridines were totally consumed in 18 h. The reaction mixture
was then evaporated to dryness and purified by flash chromatography (n-
hexane/ethyl acetate 9.8:0.2!8:2) (9, 27%). The same procedure was re-
peated by increasing the reaction temperature to reflux once the aryl-
(Z)-2,5-Dihydro-4-(4-methylpent-3-enyl)-7-nitro-1H-benzo[b]azepine
(16) and (Z)-2,5-dihydro-3-(4-methylpent-3-enyl)-7-nitro-1H-benzo[b]-
ACHTUNGTRENNUNGazide was completely consumed. After 48 h, the reaction was stopped
AHCTUNGTRENNUNG
and the mixture was purified by flash chromatography (n-hexane/ethyl
acetate 9.8:0.2!8:2) (9, 36%; 10, 7%, cis/trans 2:1).
AHCTUNGTRENNUNG
(tpp)] (10.4 mg, 1.40ꢃ10ꢀ2 mmol) and 4-nitrophenyl
azide (107 mg, 6.53ꢃ10ꢀ1 mmol) were added to a dry benzene solution
(30 mL) of myrcene (0.57 mL, 3.35 mmol). The resulting red solution was
stirred first at 658C for 12 h in a preheated oil bath and then for 18 h
more after adding silica (400 mg). The obtained red solution was evapo-
rated to dryness and the residue was purified by flash chromatography
on deactivated silica gel with use of Et3N in n-hexane (10%) during the
packing of the column (n-hexane/ethyl acetate 9:1!8:2) (17, 55%).
Method B: The reaction was repeated by increasing the temperature to
reflux after the starting arylazide had been completely consumed. A mix-
ture of 17 (43%) and 16 (17%) was recovered after 60 h as already de-
scribed for method A.
Compound 9: 1H NMR (300 MHz, CDCl3): d=7.93 (d, J=2.6 Hz, 1H;
ArH), 7.88 (dd, J=8.5, 2.6 Hz, 1H; ArH), 6.41 (d, J=8.5 Hz, 1H; ArH),
ꢀ
5.71 (m, 1H; CH=CH), 5.38 (m, 1H; CH=CH), 4.64 (m, 1H; NH CH-
ꢀ
G
E
(CH3)),
1
(CH3)); H NMR (300 MHz, C6D6): d=8.05 (d, J=
2.3 Hz, 1H; ArH), 7.96 (dd, J=8.8, 2.3 Hz, 1H; ArH), 5.80 (d, J=8.8 Hz,
1H; ArH), 5.46 (m, 1H; CH=CH), 5.08 (m, 1H; CH=CH), 4.00 (m, 1H;
ꢀ
NH CH
(CH3)), 3.63 (m, 1H; CH
(CH3)), 3.25 (brs, 1H; NH), 1.15 (m,
3H; CH3), 0.82 ppm (m, 3H; CH3); 13C NMR (100 MHz, C6D6): d=135.2
ꢀ
(CH), 129.4 (CH), 123.8 (CH), 123.1 (CH), 118.1 (CH), 49.1 (CH
(CH3)
(CH3)); MS
ꢀ
NH), 35.0 (CH
G
G
R
Chem. Eur. J. 2009, 15, 1241 – 1251
ꢂ 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
1249