Phosphonite Mediated 1,3-Dipolar Cycloaddition: a Route to Polycyclic 2- Pyrrolines from Imines, Acid Chlorides and Alkenes
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Electronic Supplementary Material (ESI) for Chemical Communications This journal is © The Royal Society of Chemistry 2013 Phosphonite Mediated 1,3-Dipolar Cycloaddition: A Route to Polycyclic 2- Pyrrolines from Imines, Acid Chlorides and Alkenes Marie S. T. Morin, Sara Aly and Bruce A. Arndtsen* 801 Sherbrooke St. W., Department of Chemistry, McGill University Montreal, Quebec H3A 2K6 Canada Supporting Information Page I. General Procedures 1 II. Imine Synthesis 2-4 III. Synthesis of Pyrrolines 3 5-8 IV. Synthesis of Pyrrolidines 4 9-10 V. Synthesis of pyrrole 5k 10 VI. References 10-11 VII. 1H and 13C NMR Spectra 12-42 I. General Procedures All reactions were performed under an inert nitrogen atmosphere in either a Vacuum Atmospheres 553-2 dry box or using Schlenk techniques. Reagents were purchased from commercial sources and used as received. Solid PPh3 and PCy3 were dried by heating at 120˚C under high vaccum. Liquid P(OCH2CF3)3, P(OPh)3 and P(NMe2)3 were dried over 4 A molecular sieves. (2-catechyl)PPh was prepared by a literature procedure.1 Aldehyde precursors to imines 2 3 4 2a,b,f-m, 2c,e and 2d were prepared by literature procedures. CDCl3 and CD3CN were distilled from CaH2 under nitrogen. Dichloromethane and diethyl ether were dried via filtration through activated molecular sieves (MBraun SPS). 1H and 13C NMR spectra were recorded on Varian Mercury 300 MHz, 400 MHz and Unity 500 MHz spectrometers. The stereochemistry of the pyrroline and pyrrolidine products was determined by NoE NMR experiments (3a, 3f, 4a and 4c), and comparison to literature reported compounds.6 1 Electronic Supplementary Material (ESI) for Chemical Communications This journal is © The Royal Society of Chemistry 2013 II. Imine Synthesis Typical Procedure To a solution of 2-(allyloxy)benzaldehyde (405.4 mg, 2.5 mmol) in dichloromethane (10 mL) was added MgSO4 and ethylamine (2.0 M in THF) (1.4 mL, 2.75 mmol). The heterogeneous mixture was stirred at room temperature for 18h. The reaction mixture was filtered, and the solvent and excess amine were evaporated in vacuo to provide imine 2a as a clear oil (402 mg, 85%). In the case of imines 2b, 2i, 2j, 2l and 2m, exactly 1.0 equivalent of amine was added. (E)-N-(2-(allyloxy)benzylidene)ethanamine 2a 1 Et H NMR (400 MHz, CDCl3): δ 8.77 (s, 1H), 7.96 (dd, J = 7.7 Hz, 1.7 Hz, 1H), N 7.34-7.29 (m, 1H), 6.97 (t, J = 7.5 Hz, 1H), 6.86 (dd, J = 8.4 Hz, 2.1 Hz, 1H), 6.11-6.01 (m, 1H), 5.41 (dt, J = 17.3 Hz, 1.6 Hz, 1H), 5.29 (dt, J = 10.6 Hz, 1.5 O Hz, 1H), 4.58-4.55 (m, 2H), 3.65 (qd, J = 7.3 Hz, 1.3 Hz, 2H), 1.30 (t, J = 7.3 13 Hz, 3H). C NMR (126 MHz; CDCl3): δ 157.6, 156.3, 133.0, 131.5, 127.3, + + 125.1, 121.0, 117.5, 112.3, 69.0, 56.2, 16.5. HRMS (ESI ) for C12H16NO ; calculated: 190.12264, found: 190.12231. (E)-N-(2-(allyloxy)benzylidene)-1-phenylmethanamine 2b 1 H NMR (400 MHz, CDCl3): δ 8.91 (s, 1H), 8.06 (dd, J = 7.7 Hz, 1.8 Hz, 1H), NBn 7.37-7.35 (m, 5H), 7.30-7.25 (m, 1H), 7.00 (t, J = 7.5 Hz, 1H), 6.92 (d, J = 8.3 Hz, 1H), 6.15-6.05 (m, 1H), 5.44 (dd, J = 17.3 Hz, 1.5 Hz, 1H), 5.34-5.31 (m, 13 1H), 4.86 (s, 2H), 4.62 (d, J = 5.1 Hz, 2H). C NMR (126 MHz, CDCl3): δ O 157.94, 157.86, 139.7, 133.0, 131.9, 128.4, 128.0, 127.5, 126.8, 124.9, 121.0, + + 117.6, 112.3, 69.1, 65.5 HRMS (ESI ) for C17H18NO ; calculated: 252.13829, found: 252.13766. (E)-N-(2-(but-3-en-1-yl)benzylidene)prop-2-en-1-amine 2c 1 H NMR (400 MHz; CDCl3): δ 8.61 (s, 1H), 7.94 (d, J = 7.7 Hz, 1H), 7.34 (td, N J = 7.4 Hz, 1.5 Hz, 1H), 7.26 (t, J = 7.6 Hz, 1H), 7.19 (d, J = 7.6 Hz 1H), 6.10 (ddt, J = 17.1 Hz, 10.4 Hz, 5.6 Hz, 1H), 5.87 (ddt, J = 17.0 Hz, 10.3 Hz, 6.7 Hz, 1H), 5.28-5.15 (m, 2H), 5.08-4.99 (m, 2H), 4.29 (dq, J = 5.6 Hz, 1.5 Hz, 2H), 2.95 (t, J = 7.9 Hz, 2H), 2.35 (q, J = 6.8 Hz, 2H). 13C NMR (126 MHz; CDCl3): δ 160.2, 141.5, 137.6, 136.0, 133.7, 130.3, 130.0, 127.7, 126.4, 115.9, 115.2, 64.0, 36.0, + + 32.1. HRMS (APCI ) for C14H18N ; calculated: 200.14287, found: 200.143338. N-(2-(allylthio)benzylidene)ethanamine 2d 1 NEt H NMR (400 MHz; CDCl3): δ 8.85 (s, 1H), 7.92 (dd, J = 7.7 Hz, 1.7 Hz, 1H), 7.40 (dd, J = 7.7 Hz, 1.4 Hz, 1H), 7.31 (td, J = 7,5 Hz, 1.7 Hz, 1H), 7.27-7.23 (m, 1H), 5.82 (ddt, J = 17.0 Hz, 10.0 Hz, 7.0 Hz, 1H), 5.07-5.01 (m, 2H), 3.67 S (qd, J = 7.3 Hz, 1.4 Hz, 2H), 3.47 (dt, J = 7.0 Hz, 1.1 Hz, 2H), 1.31 (t, J = 7.3 2 Electronic Supplementary Material (ESI) for Chemical Communications This journal is © The Royal Society of Chemistry 2013 13 Hz, 3H). C NMR (126 MHz; CDCl3): δ 159.0, 136.6, 136.1, 133.1, 131.8, 130.3, 127.8, 127.1, + + 118.0, 56.0, 38.3, 16.4. HRMS (ESI ) for C12H16NS ; calculated: 206.09980, found: 206.09928. N-(2-allylbenzylidene)ethanamine 2e 1 NEt H NMR (400 MHz, CDCl3) ppm): 8.53 (s, 1H), 7.87 (d, J = 7.5 Hz, 1H), 7.29 (t, J = 7.5 Hz, 1H), 7.23 (t, J = 7.5 Hz, 1H), 7.14 (d, J = 7.5 Hz, 1H), 6.00-5.92 (m, 1H), 5.03 (d, J = 9.0 Hz, 1H), 4.92 (d, J = 17.0 Hz, 1H), 3.63-3.57 (m, 4H), 13 1.27 (t, J = 7.5 Hz, 3H). C NMR (75.5 MHz, CDCl3) ppm): 158.8, 139.0, + + 137.2, 134.4, 130.3, 130.2, 127.5, 126.8, 116.1, 56.4, 36.9, 16.5. HRMS (APCI ) for C12H16N ; calculated: 174.12773, found: 174.12772. (E)-N-((1-allyl-1H-pyrrol-2-yl)methylene)ethanamine 2f 1 H NMR (400 MHz, CDCl3): δ 8.12 (s, 1H), 6.75 (t, J = 2.2 Hz, 1H), 6.50 (dd, J = NEt 3.7 Hz, 1.8 Hz, 1H), 6.17 (dd, J = 3.7 Hz, 2.7 Hz, 1H), 6.03-5.94 (m, 1H), 5.14- 5.11 (m, 1H), 5.04-4.96 (m, 3H), 3.51 (qd, J = 7.3 Hz, 1.2 Hz, 2H), 1.23 (t, J = 7.3 13 N Hz, 3H). C NMR (126 MHz; CDCl3): δ 151.5, 135.1, 129.4, 126.2, 116.4, 115.8, + + 108.3, 56.3, 50.6, 16.7. HRMS (APCI ) for C10H15N2 ; calculated: 163.12298, found: 163.12271. N-(2-((E)-but-2-en-1-yloxy)benzylidene)ethanamine 2h 1 NEt H NMR (500 MHz, CDCl3): δ 8.75-8.74 (m, 1H), 7.93 (dd, J = 7.7 Hz, 1.8 Hz, 1H), 7.34 (ddd, J = 8.3 Hz, 7.3 Hz, 1.8 Hz, 1H), 6.98-6.97 (m, 1H), 6.91-6.88 (m, 1H), 5.90-5.83 (m, 1H), 5.79-5.71 (m, 1H), 4.64-4.48 O Me (m, 2H), 3.67-3.62 (m, 2H), 1.78-1.74 (m, 3H), 1.29 (td, J = 7.3 Hz, 1.1 13 Hz, 3H). C NMR (75 MHz, CDCl3), with rotamers: δ 157.8, 156.5, 131.5, 130.3, 128.6, 127.2, 125.9, 125.5, 125.0, 120.9, 120.8, 112.4, 112.2, 69.1, 64.2, 56.1, 17.9, 16.4, 13.4. HRMS (ESI+) + for C13H18NO ; calculated: 204.13829, found: 204.13784. (E)-ethyl 4-(2-((E)-(hexylimino)methyl)phenoxy)but-2-enoate 2i 1 NHex H NMR (400 MHz, CDCl3) ppm): 8.73 (s, 1H), 7.95 (d, J = 8.0 Hz, 1H), 7.33 (t, J = 8.4 Hz, 1H), 7.10 (dt, J = 4.0, 16.0 Hz, 1H), 7.01 (t, J = 7.6 Hz, 1H), 6.85 (d, J = 8.4 Hz, 1H), 6.18 (d, J = 16.0 Hz, 1H), 4.75 O CO2Et (d, J = 4.0 Hz, 2H), 4.22 (q, J = 7.2 Hz, 2H), 3.63 (t, J = 6.8 Hz, 2H), 13 1.72–1.66 (m, 2H), 1.39–1.29 (m, 9H), 0.89 (t, J = 7.2 Hz, 3H); C NMR (125.7 MHz, CDCl3) ppm): 166.0, 157.0, 156.2, 142.1, 131.5, 127.6, 125.3, 122.2, 121.5, 112.0, 66.8, 62.1, 60.6, + + 31.7, 31.0, 27.0, 22.6, 14.2, 14.1; HRMS (ESI ) for C19H28NO3 ; calculated: 318.20637, found: 318.20591.