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(d, J = 18.0 Hz, 1H), 4.14 (d, J = 11.9 Hz, 1H), 3.69 (d, J = 16.5 Hz, 1H), 3.40 (dd, J = 9.2, 6.2
Hz, 1H), 3.30 (dd, J = 9.1, 4.8 Hz, 1H), 3.08 (q, J = 8.1 Hz, 1H), 2.64-2.62 (m, 1H), 2.41 (bs,
1H), 2.10-1.89 (m, 2H), 1.47 (d, J = 7.0 Hz, 3H), 1.45 (s, 3H); 13 C NMR (75 MHz, CDCl3): δ
173.6, 171.2, 171.1, 155.8, 136.9, 132.8, 128.6, 128.1, 128.1, 127.8, 71.5, 67.5, 56.1, 47.2, 45.1,
42.1, 41.7, 36.5, 35.6, 32.3, 22.7, 22.1, 20.4, 12.5; IR (thin film): ν 2947, 1775, 1746, 1705 cm -1 .
MS m/z (%) 465 (10), 437 (28), 330 (38), 91 (100); EI-HRMS calcd for C26H27NO7 m/z [M] +
465.1788; found 465.1782.
General procedure M for the Rh(I)-catalyzed cycloisomerization of ene-allenes.
Bz
MeO 2C
N
Bn
1-Benzoyl-2-benzyl-4-ethylidene-5-methyl-2,3,4,5-tetrahydro-1H-azepine-2-carboxylic acid
methyl ester (189). To a solution of ene-allene 75a (30 mg, 77 µmol) in 1,2-dichloroethane (1
mL) in a test tube, was added [Rh(CO)2Cl]2 (1.5 mg, 3.8 µmol) at rt under Ar atmosphere. The
test tube was then immersed in an oil-bath preheated to 90 °C and heating was continued for 2 h.
After this time, another portion of the catalyst was added [Rh(CO)2Cl]2 (1.5 mg, 3.8 µmol) and
the reaction was heated to 90 °C for additional 15 min when it was complete according to TLC.
The reaction mixture was then cooled to rt, and filtered through a plug of silica gel eluting with
(hexanes-EtOAc, 1 : 1, v/v) to give azepine 189 (30 mg, > 95%).
1 H NMR (300 MHz, CDCl3): δ 7.57-7.54 (m, 2H), 7.42-7.35 (m, 3H), 7.23-7.19 (m, 5H), 5.52
(q, J = 6.8 Hz, 1H), 5.03 (dd, J = 8.1, 2.5 Hz, 1H), 4.53 (dd, J = 8.1, 4.1 Hz, 1H), 4.20 (d, J =
13.6 Hz, 1H), 3.75 (s, 3H), 3.40 (bs, 1H), 3.14 (d, J = 13.6 Hz, 1H), 2.83 (d, J = 14.6 Hz, 1H),
2.66 (d, 14.6 Hz, 1H), 1.63 (d, J = 6.8 Hz, 3H), 1.08 (d, J = 7.1 Hz, 1H); 13 C NMR (CDCl3, 75
189
231