Synthesis of Aminophenanthrenes and Benzoquinolines via Hauser-Kraus Annulation of Sulfonyl Phthalide with Rauhut- Currier Adducts of Nitroalkenes Tarun Kumar, Vaijinath Mane and Irishi N. N. Namboothiri* Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400 076, India Email: irishi@chem.iitb.ac.in Entry Contents Page I X-ray Tables 1-3 1 Table S1. X-ray Crystallographic Data for 7d 1 2 Table S2. X-ray Crystallographic Data for 8 2 II Experimental Procedures and Characterization Data 3-14 1 Optimization studies and Table S3 3-4 2 Mechanistic Studies 4 3 General Information 4 4 General procedure for the synthesis of naphthoquinones 3 5 5 Scale up (1 mmol) synthesis of 2-(4-methoxyphenyl)-3-8 (3-oxobutyl)naphthalene-1,4-dione (3b) 6 General procedure for the synthesis of phenanthrenols 6 8 7 Scale up (1 mmol) synthesis of 10-(3-methoxyphenyl)-3-(pyrrolidin-1 11 yl)phenanthren-9-ol) (6a) 8 One-pot synthesis of selected phenanthrenols 6 11 9 General procedure for the synthesis of benzoquinolinols 7 11 10 Scale up (1 mmol) synthesis of 5-(4-methoxyphenyl)-2 13 methylbenzo[h]quinolin-6-ol 7a 11 One-pot synthesis of selected benzoquinolinols 7 13 12 4-(9-((4-Bromobenzyl)oxy)-10-(4-fluorophenyl)phenanthren-3-yl)- morpholine 8 14 III References 14 I. X-ray Tables 1. Table S1. X-ray Crystallographic Data for 7d Identification code INN-TK-556 Empirical formula C 20 H 14 NOCl Formula weight 319.77 Temperature 293 K Wavelength 0.71073 Å 1
Crystal system, Monoclinic space group P 1 21/c 1 Unit cell dimensions a = 8.1638(8) Å = 90 b = 14.3230(11) Å = 107.745(9) c = 13.4195(10) Å = 90 Volume 1494.5(2) Å 3 Z 4 Density (Calculated) 1.421 Mg/m 3 Absorption coefficient 0.259 mm -1 F (000) 664.0 Crystal size 0.144 x 0.128 x 0.042 mm 3 Theta range for data collection 2.14 to 31.16 Index ranges -11<=h<=11, -10<=k<=20, -18<=l<=18 Reflections collected 8424 Independent reflections 4235 [R(int) = 0.0564] Completeness to theta = 25.00 0 98.9 % Absorption correction Numerical Max. and min. transmission 0.860 and 1.000 Refinement method Full-matrix least-squares on F^2 Data / restraints / parameters 4235 / 0 / 208 Goodness-of-fit on F^2 1.076 Final R indices [I>2sigma (I)] R1 = 0.0650, wr2 = 0.1647 R indices (all data) R1 = 0.1191, wr2 = 0.2394 Largest diff. peak and hole 0.666 and -0.831 e.å -3 2. Table S2. X-ray Crystallographic Data 8 Identification code INN-MVD-965 Empirical formula C 248 H 200 Br 8 F 8 N 8 O 16 Formula weight 4339.43 Temperature 150.15 K Wavelength 0.71073 Å Crystal system, Triclinic space group P-1 Unit cell dimensions a = 15.5990(3) Å = 70.341(2) b = 18.6900(5) Å = 87.900(2) c = 19.2605(5) Å = 67.582(2) 2
Volume 4861.2(2) Å 3 Z 1 Density (Calculated) 1.482 g cm-3 Absorption coefficient 1.729 mm -1 F (000) 2224.0 Crystal size 0.110 0.105 0.085 Theta range for data collection 3.924 to 49.996 Index ranges -18 h 18, -21 k 22, -22 l 22 Reflections collected 71213 Independent reflections 16991 [R int = 0.0569, R sigma = 0.0453] Completeness to theta = 24.998 0 99.3 % Absorption correction Numerical Max. and min. transmission 1.00000 and 0.72028 Refinement method Full-matrix least-squares on F^2 Data / restraints / parameters 16991/72/1316 Goodness-of-fit on F^2 1.027 Final R indices [I>2sigma (I)] R 1 = 0.0389, wr 2 = 0.0883 R indices (all data) R 1 = 0.0527, wr 2 = 0.0958 Largest diff. peak and hole 0.79/-0.48 e.å -3 II. Experimental Procedures and Characterization Data 1. Optimization studies. At the outset, the Rauhut-Currier (RC) adduct 2a of nitroalkene with MVK and sulfonylphthalide 1 were chosen as the model Hauser-Kraus acceptor and donor, respectively, for our reaction (Table S3). When these two substrates were allowed to react in the presence of 0.5 equiv of Cs 2 CO 3 in THF at room temperature, the annulated product 3a along with the uncyclized Michael adduct 4a were isolated in almost equal proportions after 20 h (41% and 38%, respectively, entry 1). Similar results were observed, though the reaction time was long (32 h), when K 2 CO 3 (0.5 equiv) was used as the base (38% and 35% yields, respectively, entry 2). An increment in the amount of Cs 2 CO 3 to 1.0 equiv accelerated the reaction and facilitated the formation of annulated product 3a in higher yield (58%) as opposed to the Michael adduct 4a which was isolated in much lower yield (15%, entry 3). However, there was no reaction when triethylamine was used as the base leading to recovery of both starting materials after 24 h (entry 4). Higher Cs 2 CO 3 loading (1.5 equiv) improved the ratio further and the annulated product 3a was isolated in higher yield (65%) with a corresponding decrease in the yield of the Michael adduct 4a (12%, entry 5). Further increasing the loading of Cs 2 CO 3, though lowered the reaction time to 7 h, did not improve the yield (64% and 10% respectively, entry 6). A strong base such as t-buok resulted in complex reaction mixture (entry 7). Replacing THF with a halogenated solvent such as CH 2 Cl 2 or a hydrocarbon solvent such as benzene not only slowed down the reaction but also lowered the product ratio with competition from the Michael adduct 4a (entries 8-9). Finally, the reaction using 1.5 equiv of Cs 2 CO 3 in THF at room temperature (entry 5) was identified as the optimal one for investigating the substrate scope. 3
Table S3. Optimization of Reaction Conditions entry base (equiv) solvent time (h) yield/% a 3a yield/% a 4a 1 Cs 2 CO 3 (0.5) THF 20 41 38 2 K 2 CO 3 (0.5) THF 32 38 35 3 Cs 2 CO 3 (1.0) THF 12 58 15 4 TEA (1.0) THF 24 - b - b 5 Cs 2 CO 3 (1.5) THF 10 65 12 6 Cs 2 CO 3 (2.0) THF 7 64 10 7 KO t Bu (1.5) THF 1 - c - c 8 Cs 2 CO 3 (1.5) DCM 11 42 27 9 Cs 2 CO 3 (1.5) Benzene 24 41 29 a After silica gel column chromatography. b No reaction. c Complex mixture. 2. Mechanistic Studies The reaction of quinone 3a with a secondary amine, viz pyrrolidine, leading to the formation of aminophenanthrenol 6a under the standard conditions was monitored by 1 H NMR and mass spectrometry. While only gradual disappearance of the starting materials and formation of the product 6a could be observed by 1 H NMR, mass spectrometry provided evidence for the fleeting intermediacy of aminal (precursor of iminium IV, Scheme 3, main text, MH + = m/z 406). Similar reaction of 3a with a primary amine, viz benzylamine, confirmed the intermediacy of enamine V (MH + = m/z 424). Attempts to characterize the enamine VIIIb, derived from ammonia, were unsuccessful. 3. General Information. The melting points recorded are uncorrected. NMR spectra ( 1 H, 1 H decoupled 13 C and 1 H- 1 H COSY) were recorded with TMS as the internal standard. The coupling constants (J values) are given in Hz. High resolution mass spectra were recorded under ESI Q-TOF conditions. X-ray data were collected on a diffractometer equipped with graphite monochromated Mo K radiation. The structure was solved by direct methods shelxs97 and refined by full-matrix least squares against F 2 using shelxl97 software. Sulfonylphthalide 1 and RC adducts of nitroalkenes 2 were prepared by literature methods. 4
4. General procedure for the synthesis of naphthoquinones 3. To a stirred solution of sulfonyl phthalide 1 (90 mg, 0.33 mmol, 1.1 equiv) in THF (4 ml), Cs 2 CO 3 (146 mg, 0.45 mmol, 1.5 equiv) was added. After 5 min, the RC adduct of nitroalkene 2 (0.3 mmol, 1 equiv) was added and the reaction mixture was stirred untill the completion of reaction. The solvent was removed in vacuo and the crude residue was directly subjected to silica gel column chromatography and the product was isolated by gradient elution with ethyl acetate/petroleum ether (10:90 to 18:82). 3-(1-(3-Methoxyphenyl)-2-nitro-5-oxohexyl)-3-(phenylsulfonyl)isobenzofuran-1(3H)-one (4a) White solid; Yield 19 mg, 12%; mp 75-78 o C; IR (KBr, cm -1 ) 3021 (w), 2935 (w), 1795 (vs), 1716 (m), 1555 (m), 1153 (s), 758 (s); 1 H NMR (400 MHz, CDCl 3 ) 2.14 (s, 3H), 2.16-2.25 (m, 1H), 2.44-2.52 (m, 1H), 2.55-2.67 (m, 2H), 3.67 (s, 3H), 5.13 (d, J = 5.7 Hz, 1H), 5.60 (ddd, J = 5.7, 3.9, 1.8 Hz, 1H), 6.65-6.69 (m, 3H), 7.03 (t, J = 7.8 Hz, 1H), 7.23 (t, J = 7.9 Hz, 2H), 7.29-7.35 (m, 2H), 7.40 (d, J = 7.4 Hz, 2H), 7.45 (t, J = 7.6, 1.1 Hz, 1H), 7.56 (td, J = 6.4, 2.2 Hz, 1H), 7.64 (d, J = 7.8 Hz, 1H); 13 C NMR (125 MHz, CDCl 3 ) 24.4, 30.1, 40.4, 49.9, 55.4, 87.5, 99.8, 114.9, 125.5, 125.6, 126.2, 128.9 ( 2), 129.8, 130.4 ( 2), 131.2, 132.4, 132.5, 134.5, 135.0, 143.4, 159.5, 166.7, 206.5; MS (ES+, Ar) m/z (rel intensity) 562 (MK +, 10), 546 (MNa +, 100), 523 (15); HRMS (ES+) calcd for C 27 H 25 O 8 NSNa (MNa +, 100) 546.1193, found 546.1197. 2-(3-Methoxyphenyl)-3-(3-oxobutyl)naphthalene-1,4-dione (3a) Light yellow solid; Yield 65 mg, 65%; mp 82-84 o C; IR (KBr, cm -1 ) 3016 (w), 2932 (w), 1716 (s), 1661 (vs), 1596 (s), 1579 (m), 1327 (m), 1284 (s), 1246 (m), 1039 (m), 767 (vs), 721 (s); 1 H NMR (400 MHz, CDCl 3 ) 2.07 (s, 3H), 2.59 (t, J = 7.7 Hz, 2H), 2.74 (t, J = 7.7 Hz, 2H), 3.82 (s, 3H), 6.71-6.72 (m, 1H), 6.75 (dt, J = 7.9, 1.0 Hz, 1H), 6.95 (ddd, J = 7.9, 2.5, 1.0 Hz, 1H), 7.37 (t, J = 7.9 Hz, 1H), 7.74-7.76 (m, 2H), 8.09-8.14 (m, 2H); 13 C NMR (125 MHz, CDCl 3 ) 22.9, 29.7, 42.7, 55.4, 114.2, 114.7, 121.1, 126.4, 126.8, 129.7, 132.1, 132.3, 133.8, 134.0, 134.7, 146.7, 147.1, 159.6, 184.3, 185.4, 206.7; MS (ES+, Ar) m/z (rel intensity) 358 ([MNa+1] +, 18), 357 (MNa +, 100); HRMS (ES+) calcd for C 21 H 18 O 4 Na (MNa +, 100) 357.1097, found 357.1098. 2-(4-Methoxyphenyl)-3-(3-oxobutyl)naphthalene-1,4-dione (3b) Yellow solid; Yield 64 mg, 64%; mp 95-97 o C; IR (KBr, cm -1 ) 2925 (w), 1713 (m), 1659 (vs), 1609 (m), 1288 (s), 1248 (s), 1177 (m), 1028 (m); 1 H NMR (400 MHz, CDCl 3 ) 2.07 (s, 3H), 2.59 (t, J = 7.8 Hz, 2H), 2.78 (t, J = 7.8 Hz, 2H), 3.85 (s, 3H), 6.97 (d, J = 8.7 Hz, 2H), 7.12 (d, J = 8.7 Hz, 2H), 7.72-7.75 (m, 2H), 8.08-8.13 (m, 2H); 13 C NMR (100 MHz, CDCl 3 ) 22.9, 29.6, 42.7, 55.4, 113.9, 125.4, 126.3, 126.7, 130.5, 132.1, 132.3, 133.7, 133.8, 146.4, 146.9, 160.0, 184.5, 185.5, 206.8; MS (ES+, Ar) m/z (rel intensity) 373 (MK +, 2), 358 ([MNa+1] +, 18), 357 (MNa +, 100); HRMS (ES+) calcd for C 21 H 18 O 4 Na (MNa +, 100) 357.1097, found 357.1098. 5
2-(3,4-Dimethoxyphenyl)-3-(3-oxobutyl)naphthalene-1,4-dione (3c) Orange solid; Yield 71 mg, 64%; mp 112-114 o C; IR (KBr, cm -1 ) 2934 (m), 1715 (s), 1661 (vs), 1595 (m), 1515 (vs), 1266 (vs), 1255 (vs), 1170 (m), 1141 (m), 1025 (m); 1 H NMR (500 MHz, CDCl 3 ) 2.06 (s, 3H), 2.59 (t, J = 7.8 Hz, 2H), 2.78 (t, J = 7.8 Hz, 2H), 3.86 (s, 3H), 3.91 (s, 3H), 6.70 (d, J = 1.8 Hz, 1H), 6.74 (dd, J = 8.2, 1.8 Hz, 1H), 6.94 (d, J = 8.2 Hz, 1H), 7.71-7.74 (m, 2H), 8.07-8.11 (m, 2H); 13 C NMR (125 MHz, CDCl 3 ) 23.0, 29.7, 42.8, 56.0, 56.1, 111.1, 112.4, 121.7, 125.7, 126.4, 126.8, 132.1, 132.3, 133.8, 133.9, 146.6, 146.9, 148.9, 149.5, 184.5, 185.5, 206.8; MS (ES+, Ar) m/z (rel intensity) 387 (MNa +, 100), 365 (22), 307 (90), 295 (12), 233 (11); HRMS (ES+) calcd for C 22 H 20 O 5 Na (MNa +, 100) 387.1203, found 387.1206. 2-(3-Oxobutyl)-3-p-tolylnaphthalene-1,4-dione (3d) Light yellow solid; Yield 54 mg, 57%; mp 92-94 o C; IR (KBr, cm -1 ) 2926 (w), 1715 (s), 1660 (vs), 1595 (m), 1328 (m), 1296 (s), 1264 (m), 721 (m); 1 H NMR (400 MHz, CDCl 3 ) 2.07 (s, 3H), 2.41 (s, 3H), 2.59 (t, J = 7.9 Hz, 2H), 2.75 (t, J = 7.9 Hz, 2H), 7.07 (d, J = 7.9 Hz, 2H), 7.26 (d, J = 7.9 Hz, 2H), 7.73-7.75 (m, 2H), 8.09-8.14 (m, 2H); 13 C NMR (100 MHz, CDCl 3 ) 21.5, 22.9, 29.7, 42.8, 126.4, 126.8, 128.9, 129.3, 130.4, 132.2, 132.4, 133.8, 134.0, 138.8, 146.5, 147.4, 184.6, 185.6, 207.0; MS (ES+, Ar) m/z (rel intensity) 357 (MK +, 7), 341 (MNa +, 100); HRMS (ES+) calcd for C 21 H 18 O 3 Na (MNa +, 100) 341.1148, found 341.1145. 2-(3-Oxobutyl)-3-phenylnaphthalene-1,4-dione (3e) Light yellow solid; Yield 57 mg, 62%; mp 90-92 o C; IR (KBr, cm -1 ) 3062 (w), 2925 (w), 1716 (s), 1661 (vs), 1595 (m), 1296 (s), 1267 (m), 1162 (w), 758 (m), 736 (m), 720 (m), 704 (m); 1 H NMR (400 MHz, CDCl 3 ) 2.06 (s, 3H), 2.59 (t, J = 7.8 Hz, 2H), 2.74 (t, J = 7.8 Hz, 2H), 7.18-7.20 (m, 2H), 7.42-7.48 (m, 3H), 7.74-7.77 (m, 2H), 8.09-8.15 (m, 2H); 13 C NMR (125 MHz, CDCl 3 ) 22.9, 29.7, 42.7, 126.5, 126.8, 128.5, 128.8, 128.9, 132.2, 132.3, 133.4, 133.9, 134.0, 146.7, 147.3, 184.4, 185.5, 206.8; MS (ES+, Ar) m/z (rel intensity) 343 (MK +, 70), 328 ([MNa+1] +, 82), 327 (MNa +, 100), 312 (7), 247 (23); HRMS (ES+) calcd for C 20 H 16 O 3 Na (MNa +, 100) 327.0992, found 327.0985. 2-(4-Fluorophenyl)-3-(3-oxobutyl)naphthalene-1,4-dione dione (3f) Light yellow solid; Yield 67 mg, 70%; mp 106-108 o C; IR (KBr, cm -1 ) 3067 (vw), 2922 (vw), 1716 (s), 1663 (vs), 1596 (m), 1508 (w), 1296 (m), 1224 (m), 1160 (w), 737 (s); 1 H NMR (500 MHz, CDCl 3 ) 2.07 (s, 3H), 2.59 (t, J = 7.8 Hz, 2H), 2.73 (t, J = 7.8 Hz, 2H), 7.19-7.13 (m, 4H), 7.72-7.77 (m, 2H), 8.07-8.10 (m, 1H), 8.11-8.14 (m, 1H); 13 C NMR (125 MHz, CDCl 3 ) 22.9, 29.7, 42.6, 115.7 (d, J = 22.5 Hz), 126.5, 126.8, 129.2 (d, J = 3.8 Hz), 131.0 ( 2), 132.1, 132.3, 134.0 (d, J = 17.5 Hz), 146.3, 146.9, 162.9 (d, J = 246.3 Hz), 184.3, 185.3, 206.6; 19 F NMR (470 MHz, CDCl 3 ) -112.5; MS (ES+, Ar) 6
m/z (rel intensity) 361 (MK +, 40), 347 ([MNa + 2] +, 15), 346 (MNa + 1] +, 93), 345 (MNa +, 100); HRMS (ES+) calcd for C 20 H 15 O 3 FNa (MNa +, 100) 345.0897, found 345.0895. 2-(4-Chlorophenyl)-3-(3-oxobutyl)naphthalene-1,4-dione (3g) Light yellow solid; Yield 63 mg, 62%; mp 140-142 o C; IR (KBr, cm -1 ) 2915 (vw), 1706 (s), 1663 (vs), 1594 (w), 1295 (s), 1090 (w), 722 (w); 1 H NMR (500 MHz, CDCl 3 ) 2.08 (s, 3H), 2.60 (t, J = 7.7 Hz, 2H), 2.73 (t, J = 7.7 Hz, 2H), 7.14 (d, J = 8.4 Hz, 2H), 7.44 (d, J = 8.4 Hz, 2H), 7.73-7.77 (m, 2H), 8.10-8.08 (m, 1H), 8.14-8.12 (m, 1H); 13 C NMR (125 MHz, CDCl 3 ) 23.0, 29.8, 42.6, 126.5, 126.9, 128.9, 130.5, 131.8, 132.1, 132.3, 134.0, 134.1, 135.0, 146.1, 147.0, 184.2, 185.3, 206.6; MS (ES+, Ar) m/z (rel intensity) 379 ([MK+2] +, 11), 377 (MK +, 33), 363 [MNa+2] +, 33), 361 (MNa +, 100), 327 (21); HRMS (ES+) calcd for C 20 H 15 O 3 ClNa (MNa +, 100) 361.0602, found 361.0604. 2-(4-Bromophenyl)-3-(3-oxobutyl)naphthalene-1,4-dione (3h) Light yellow solid; Yield 76 mg, 66%; mp 139-141 o C; IR (KBr, cm -1 ) 2925 (vw), 1716 (s), 1661 (vs), 1593 (m), 1487 (m), 1327 (m), 1294 (vs), 1163 (w), 1072 (w), 1011 (w), 811 (w), 720 (m); 1 H NMR (400 MHz, CDCl 3 ) 2.08 (s, 3H), 2.59 (t, J = 7.6 Hz, 2H), 2.73 (t, J = 7.6 Hz, 2H), 7.07 (d, J = 8.4 Hz, 2H), 7.59 (d, J = 8.4 Hz, 2H), 7.73-7.78 (m, 2H), 8.07-8.14 (m, 2H); 13 C NMR (125 MHz, CDCl 3 ) 23.0, 29.8, 42.6, 123.3, 126.5, 126.9, 130.8, 131.8, 132.1, 132.2, 132.3, 134.0, 134.1, 146.2, 146.9, 184.1, 185.3, 206.6; MS (ES+, Ar) m/z (rel intensity) 407 ([MNa + 2] +, 98), 405 (MNa +, 100), 385 (14), 383 (14); HRMS (ES+) calcd for C 20 H 15 O 3 BrNa (MNa +, 100) 405.0097, found 405.0104. 3'-(3-oxobutyl)-[1,2'-binaphthalene]-1',4'-dione (3i) Brown oil; Yield 66 mg, 62%; IR (KBr, cm -1 ) 2919 (m), 2850 (w), 1715 (s), 1662 (vs), 1594 (w), 1295 (s), 1270 (m), 1162 (w), 799 (w); 1 H NMR (400 MHz, CDCl 3 ) 1.93 (s), 2.47-2.55 (m, 3H), 2.63-2.71 (m, 1H), 7.28 (d, J = 7.5 Hz, 1H), 7.42 (td, J = 7.6, 1.1 Hz, 1H), 7.48 (d, J = 7.6 Hz, 1H), 7.50 (t, J = 7.5 Hz, 1H), 7.55 (d, J = 7.5 Hz, 1H), 7.78 (ddd collapsed to t, J = 6.8, 1.7 Hz, 2H), 7.92 (t, J = 7.6 Hz, 2H), 8.11 (dd, J = 6.8, 1.7 Hz, 1H), 8.21 (dd, J = 6.8, 1.7 Hz, 1H); 13 C NMR (100 MHz, CDCl 3 ) 23.2, 29.5, 42.5, 124.9, 125.4, 126.3, 126.4, 126.6, 126.8, 126.9, 128.9, 129.4, 131.4 ( 2), 132.3, 132.5, 133.7, 133.9, 134.1, 146.7, 148.6, 184.2, 185.2, 206.6; MS (ES+, Ar) m/z (rel intensity) 393 (MK +, 15), 377 (MNa +, 100); HRMS (ES+) calcd for C 24 H 18 O 3 Na (MNa +, 100) 377.1148, found 377.1142. 2-(Furan-2-yl)-3-(3-oxobutyl)naphthalene-1,4-dione (3j) Brown solid; Yield 66 mg, 75%; mp 89-91 o C; IR (KBr, cm -1 ) 3139 (vw), 2922 (vw), 1706 (vs), 1670 (s), 1644 (m), 1294 (s), 1266 (m), 1163 (w); 1 H NMR (400 MHz, CDCl 3 ) 2.19 (s, 3H), 2.76 (t, J = 7.9 Hz, 2H), 3.13 (t, J = 7.9 Hz, 2H), 6.61 (dd, J = 3.4, 1.5 Hz, 1H), 7.26 (d, J = 3.5 Hz, 1H), 7.59 (d, J = 1.5 Hz, 1H), 7.72 (dd, J = 6.1, 3.5 Hz, 2H), 8.09 (td, J = 6.1, 3.5 Hz, 2H); 13 C NMR (125 MHz, CDCl 3 ) 22.9, 29.9, 43.4, 112.7, 118.9, 126.4, 126.8, 132.1, 132.4, 133.8, 133.9, 144.0 ( 2), 144.6, 146.9, 183.4, 7
185.2, 207.4; MS (ES+, Ar) m/z (rel intensity) 318 ([MNa + 1] +, 90), 317 (MNa +, 100), 295 (18), 237 (20); HRMS (ES+) calcd for C 18 H 14 O 4 Na (MNa + ) 317.0784, found 317.0781. 5. Scale up (1 mmol) synthesis of 2-(4-methoxyphenyl)-3-(3-oxobutyl)naphthalene-1,4-dione (3b). To a stirred solution of sulfonyl phthalide 1 (301 mg, 1.1 mmol, 1.1 equiv) in THF (9 ml), Cs 2 CO 3 (489 mg, 1.5 mmol, 1.5 equiv) was added. After 5 min, the RC adduct of nitroalkene 2b (249 mg, 1.0 mmol, 1 equiv) was added and the reaction mixture was stirred until the completion of reaction (10 h). The solvent was removed in vacuo and the crude residue was directly subjected to silica gel column chromatography and the product 3b was isolated in 64% (213 mg) by gradient elution with ethyl acetate/petroleum ether (15:85). 6. General procedure for the synthesis of phenanthrenols 6. To a stirred solution of naphthoquinone 3 (0.2 mmol, 1 equiv) and amine (0.2 mmol, 1 equiv) in toluene (4 ml), catalytic amount of p-tsoh (10 mg, 0.06 mmol, 30 mol %) was added and the resulting reaction mixture was subjected to reflux. After the completion of reaction (monitored by TLC), the reaction mixture was concentrated in vacuo and the residue was purified by silica gel column chromatography by gradient elution with ethyl acetate/petroleum ether (2:98 to 9:91). 10-(3-Methoxyphenyl)-3-(pyrrolidin-1-yl)phenanthren-9-ol) (6a) Light yellow solid; Yield 58 mg, 79%; mp 184-186 o C; IR (KBr, cm -1 ) 3535 (m), 2965 (m), 2834 (m), 1619 (s), 1597 (s), 1524 (w), 1504 (w), 1486 (w), 1449 (m), 1374 (m), 1287 (w), 1063 (w), 1043 (m), 811 (vs); 1 H NMR (400 MHz, CDCl 3 ) 2.05-2.15 (unresolved m, 4H), 3.40-3.50 (unresolved m, 4H), 3.85 (s, 3H), 5.31 (br s, 1H), 6.88-6.92 (br unresolved m, 1H), 7.00-7.02 (br unresolved m, 1H), 7.06 (d, J = 7.9 Hz, 2H), 7.33 (d, J = 8.5 Hz, 1H), 7.52 (t, J = 7.9 Hz, 1H), 7.62-7.68 (m, 3H), 8.34 (dd, J = 7.7, 1.8 Hz, 1H), 8.65 (d, J = 7.7 Hz, 1H); 13 C NMR (100 MHz, CDCl 3 ) 25.7, 48.1, 55.5, 102.7, 114.5, 114.7, 116.5, 117.6, 122.8, 123.1, 123.3, 123.6, 125.7, 126.4, 126.5, 128.0, 130.4, 130.8, 136.7, 142.7, 145.2, 145.2, 160.7; MS (ES+, Ar) m/z (rel intensity) 370 (MH +, 60), 369 (M +, 45), 368 ([M-H] +, 100); HRMS (ES+) calcd for C 25 H 24 NO 2 (MH +, 60) 370.1802, found 370.1810. 10-(3,4-Dimethoxyphenyl)-3-(pyrrolidin-1-yl)phenanthren-9-ol (6b) Light yellow solid; Yield 62 mg, 78%; mp 225-227 o C; IR (KBr, cm -1 ) 2962 (m), 2924 (s), 2850 (m), 1615 (w), 1595 (w), 1512 (m), 1463 (w), 1440 (w), 1254 (m), 1219 (w), 1025 (m), 762 (vs); 1 H NMR (400 MHz, CDCl 3 ) 2.08 (unresolved m, 4H), 3.46 (unresolved m, 4H), 3.88 (s, 3H), 3.99 (s, 3H), 5.33 (br s, 1H), 6.89 (d, J = 8.4 Hz, 1H), 6.95-6.97 (br unresolved m, 1H), 7.03, 7.09 (ABq, J = 8.1 Hz, 2H), 7.32 (d, J = 8.4 Hz, 1H), 7.61-7.67 (m, 3H), 8.33 (dd, J = 7.9, 2.0 Hz, 1H), 8.65 (d, J = 7.9 Hz, 1H); 13 C NMR (125 MHz, CDCl 3 ) 25.7, 48.2, 56.1, 56.2, 102.8, 112.2, 112.3, 114.3, 114.7, 117.4, 122.8, 123.1, 123.7, 125.7, 126.6, 127.3, 128.0, 130.3, 143.0, 145.3, 149.2, 149.2, 150.0, 150.1; MS (ES+, Ar) m/z (rel intensity) 400 ([MH +, 10), 399 (M +, 35), 398 ([M-H] +, 100); HRMS (ES+) calcd for C 26 H 25 NO 3 (M +, 35) 399.1829, found 399.1836. 8
10-(4-Fluorophenyl)-3-morpholinophenanthren-9-ol (6c) Light yellow solid; Yield 63 mg, 84%; mp 172-173 o C; IR (KBr, cm -1 ) 3409 (br s), 2966 (w), 2922 (w), 2855 (w), 1615 (w), 1597 (m), 1505 (s), 1444 (m), 1267 (w), 1221 (vs), 1117 (m), 945 (m), 763 (vs); 1 H NMR (500 MHz, CDCl 3 ) 3.32 (br t, J = 4.6 Hz, 4H), 3.95 (br t, J = 4.6 Hz, 4H), 5.25 (br s, 1H), 7.17 (d, J = 8.8 Hz, 1H), 7.27 (d, J = 8.8 Hz, 1H), 7.31 (t, J = 8.5 Hz, 2H), 7.45 (dd, J = 8.5, 5.6 Hz, 2H), 7.64-7.71 (m, 2H), 8.08 (br unresolved m, 1H), 8.36 (dd, J = 8.4, 1.2 Hz, 1H), 8.65 (d, J = 8.1 Hz, 1H); 13 C NMR (125 MHz, CDCl 3 ) 50.4, 67.2, 107.9, 116.3, 117.0 (d, J = 21.3 Hz), 118.4, 122.6, 123.3, 125.5, 126.3, 126.9, 127.1, 127.5, 130.6 (d, J = 3.8 Hz), 130.7, 133.4 (d, J = 8.8 Hz), 144.8, 148.3, 163.0 (d, J = 246.3 Hz); 19 F NMR (470 MHz, CDCl 3 ) -113.0; MS (ES+, Ar) m/z (rel intensity) 374 (MH +, 95), 373 (M +, 100); HRMS (ES+) calcd for C 24 H 21 FNO 2 (MH + ) 374.1551, found 374.1538. 3-(Benzylamino)-10-(4-fluorophenyl)phenanthren-9-ol (6d) Light yellow solid; Yield 64 mg, 82%; IR (KBr, cm -1 ) 3543 (m), 3410 (br m), 3065 (w), 3029 (w), 2922 (w), 2851 (w), 1621 (s), 1599 (s), 1506 (vs), 1441 (m), 1250 (m), 1223 (s), 1157 (m), 1061 (m), 830 (m), 761 (vs); 1 H NMR (500 MHz, CDCl 3 ) 4.51 (s, 2H), 5.14 (br s, 1H), 6.87 (dd, J = 8.8, 2.2 Hz, 1H), 7.16 (d, J = 8.8 Hz, 1H), 7.28-7.32 (m, 3H), 7.38 (t, J = 7.1 Hz, 2H), 7.42-7.47 (m, 4H), 7.62-7.66 (m, 2H), 7.79 (d, J = 2.2 Hz, 1H), 8.34 (dd, J = 7.2, 4.1 Hz, 1H), 8.53 (dd, J = 7.2, 4.1 Hz, 1H); 13 C NMR (100 MHz, CDCl 3 ) 48.9, 103.6, 116.4, 116.6, 116.9 (d, J = 21.0 Hz), 122.7, 123.1, 125.1, 125.5, 126.5, 126.7 (d, J = 7.0 Hz), 127.5, 127.8, 128.0, 128.9, 130.3, 130.8, 130.9, 133.4 (d, J = 8.0 Hz), 139.5, 143.6, 145.1, 162.9 (d, J = 246.0 Hz); 19 F NMR (376 MHz, CDCl 3 ) -113.1; MS (ES+, Ar) m/z (rel intensity) 394 (MH +, 75), 393 (M +, 48), 392 ([M-H] +, 100); HRMS (ES+) calcd for C 27 H 21 FNO (MH + ) 394.1602, found 394.1597. Ethyl (10-(4-fluorophenyl)-9-hydroxyphenanthren-3-yl)prolinate (6e) Light green oil; Yield 75 mg, 87%; IR (neat, cm -1 ) 3437 (br vs), 2976 (vw), 1733 (m), 1618 (m), 1599 (m), 1505 (s), 1445 (m), 1371 (m), 1291 (w), 1224 (m), 1158 (m), 759 (vs); 1 H NMR (500 MHz, CDCl 3 ) 1.27 (t, J = 7.1 Hz, 3H), 2.11-2.15 (m, 1H), 2.21-2.32 (m, 2H), 2.33-2.39 (m, 1H), 3.54 (ddd collapsed to br q, J = 7.2 Hz, 1H), 3.76 (br unresolved m, 1H), 4.15-4.28 (m, 2H), 4.43 (d, J = 7.4 Hz, 1H), 5.20 (br s, 1H), 6.84 (d, J = 8.6 Hz, 1H), 7.21 (d, J = 8.6 Hz, 1H), 7.29 (t, J = 7.5 Hz, 2H), 7.41-7.46 (br unresolved m, 2H), 7.64-7.68 (m, 2H), 7.71-7.73 (br unresolved, 1H), 8.34 (d, J = 7.7 Hz, 1H), 8.61 (d, J = 7.7 Hz, 1H); 13 C NMR (125 MHz, CDCl 3 ) 14.5, 24.1, 31.0, 48.8, 61.2, 61.4, 103.5, 114.6, 116.5, 116.8 (d, J = 21.3 Hz), 122.7, 123.1, 124.3, 125.6, 126.4, 126.6, 126.7, 127.9, 130.5, 130.9, 133.4 (d, J = 7.5 Hz), 143.4, 143.9, 162.9 (d, J = 246.3 Hz), 174.7; 19 F NMR (470 MHz, CDCl 3 ) -113.3; MS (ES+, Ar) m/z (rel intensity) 429 (M +, 25), 428 ([M-H] +, 100); HRMS (ES+) calcd for C 27 H 24 FNO 3 (M + ) 429.1735, found 429.1735. 9
Ethyl (9-hydroxy-10-(4-methoxyphenyl)phenanthren-3-yl)valinate (6f) Light yellow solid; Yield 78 mg, 91%; mp 109-110 o C; IR (KBr, cm - 1 ) 3405 (br vs), 2962 (vw), 2928 (vw), 1730 (s), 1647 (m), 1480 (w), 1437 (w), 1265 (w), 1164 (w), 741 (m), 700 (w); 1 H NMR (500 MHz, CDCl 3 ) 1.11 (d, J = 6.8 Hz, 3H), 1.34 (d, J = 6.8 Hz, 3H), 1.27 (t, J = 7.1 Hz, 3H), 2.18-2.26 (m, 1H), 3.91 (s, 3H), 4.07 (d, J = 6.2 Hz, 1H), 4.20 (q, J = 7.1 Hz, 2H), 5.32 (br s, 1H), 6.89 (dd, J = 8.7, 1.9 Hz, 1H), 7.12 (d, J = 8.3 Hz, 2H), 7.24 (d, J = 8.7 Hz, 1H), 7.37 (d, J = 8.3 Hz, 2H), 7.62-7.67 (m, 2H), 7.83 (br unresolved m, 1H), 8.34 (dd, J = 8.1, 2.0 Hz, 1H), 8.59 (d, J = 8.1 Hz, 1H); 13 C NMR (125 MHz, CDCl 3 ) 14.5, 19.1, 19.4, 31.8, 55.5, 61.1, 63.2, 104.6, 115.2, 116.8, 117.2, 122.7, 123.1, 125.6, 126.0, 126.6 ( 2), 126.7, 126.8, 127.8, 130.2, 132.7, 143.9, 144.1, 159.8, 174.0; MS (ES+, Ar) m/z (rel intensity) 444 (MH +, 25), 443 (M +, 27), 442 (100); HRMS (ES+) calcd for C 28 H 30 NO 4 (MH + ) 444.2169, found 444.2158. Ethyl (9-hydroxy-10-(p-tolyl)phenanthren-3-yl)valinate (6g) Light green oil; Yield 79 mg, 92%; IR (neat, cm -1 ) 3399 (br vs), 2966 (w), 2932 (w), 1730 (vs), 1693 (w), 1601 (m), 1507 (w), 1266 (m), 1156 (w), 1022 (m), 763 (s), 739 (vs); 1 H NMR (400 MHz, CDCl 3 ) 1.14 (d, J = 6.8 Hz, 3H), 1.17 (d, J = 6.8 Hz, 3H), 1.30 (t, J = 7.1 Hz, 3H), 2.21-2.29 (m, 1H), 2.50 (s, 3H), 4.11 (d, J = 6.2 Hz, 1H), 4.24 (q, J = 7.1 Hz, 2H), 4.45 (br s, 1H), 5.40 (s, 1H), 6.92 (dd, J = 8.8, 2.3 Hz, 1H), 7.29 (d, J = 8.8 Hz, 1H), 7.37, 7.41 (ABq, J = 8.3 Hz, 4H), 7.69-7.64 (m, 2H), 7.87 (d, J = 2.3 Hz, 1H), 8.37-8.41 (m, 1H), 8.61-8.65 (m, 1H); 13 C NMR (100 MHz, CDCl 3 ) 14.5, 19.1, 19.3, 21.5, 31.7, 61.1, 63.1, 104.4, 116.8, 117.5, 122.6, 123.1, 125.6, 125.7, 126.6 ( 2), 126.8, 127.8, 130.2, 130.5, 131.3, 131.8, 138.2, 143.6, 144.1, 174.0; MS (ES+, Ar) m/z (rel intensity) 466 (MK+, 22), 450 (MNa +, 23), 428 (MH +, 100), 427 (M+, 35), 426 ([M-H] +, 100); HRMS (ES+) calcd for C 28 H 30 NO 3 (MH + ) 428.2220, found 428.2221. Ethyl (10-(4-fluorophenyl)-9-hydroxyphenanthren-3-yl)valinate (6h) Light green oil; Yield 78 mg, 91%; IR (neat, cm -1 ) 3400 (br w), 2967 (w), 1728 (s), 1613 (m), 1599 (s), 1505 (s), 1216 (m), 1157 (m), 758 (vs); 1 H NMR (500 MHz, CDCl 3 ) 1.13 (d, J = 6.8 Hz, 3H), 1.17 (d, J = 6.8 Hz, 3H), 1.30 (t, J = 7.1 Hz, 3H), 2.21-2.23 (m, 1H), 4.10 (d, J = 6.1 Hz, 1H), 4.23 (q, J = 6.4 Hz, 2H), 4.50 (br s, 1H), 5.28 (s, 1H), 6.89 (dd, J = 8.8, 1.7 Hz, 1H), 7.17 (d, J = 8.8 Hz, 1H), 7.29 (d, J = 6.5 Hz, 2H), 7.41 (t, J = 6.5 Hz, 2H), 7.64-7.68 (m, 2H), 7.85 (d, J = 1.7 Hz, 1H), 8.37 (d, J = 8.0 Hz, 1H), 8.60 (d, J = 8.0 Hz, 1H); 13 C NMR (125 MHz, CDCl 3 ) 14.4, 19.0, 19.2, 31.7, 61.0, 63.1, 104.4, 116.6, 116.7, 116.8 ( 2), 122.6, 123.0, 125.5, 126.4, 126.7 (d, J = 11.3 Hz), 127.8, 130.2, 130.7 ( 2), 133.2 (d, J = 7.5 Hz), 143.7, 144.2, 162.8 (d, J = 246.3 Hz), 173.9; 19 F NMR (470 MHz, CDCl 3 ) -113.2; MS (ES+, Ar) m/z (rel intensity) 432 (MH +, 40), 430 (100), 413 (10), 402 (18), 390 (10), 374 (22); HRMS (ES+) calcd for C 27 H 27 FNO 3 (MH + ) 432.1969, found 432.1964. 10
Ethyl (10-(4-fluorophenyl)-9-hydroxyphenanthren-3-yl)tryptophanate (6i) Light yellow oil; Yield 93 mg, 90%; IR (neat, cm -1 ) 3406 (br vs), 3057 (w), 2981 (w), 2929 (w), 1728 (vs), 1618 (m), 1598 (s), 1506 (vs), 1265 (s), 1226 (vs), 1158 (m), 1026 (m), 832 (m), 764 (s), 740 (vs); 1 H NMR (500 MHz, CDCl 3 ) 1.18 (t, J = 6.9 Hz, 3H), 3.36 (dd, J = 14.5, 6.6 Hz, 1H), 3.49 (dd, J = 14.5, 5.6 Hz, 1H), 4.09-4.18 (m, 2H), 4.61 (t, J = 5.9 Hz, 1H), 5.13 (s, 1H), 6.83-7.41 (m, 10H), 7.58-7.61 (m, 2H), 7.66-7.68 (m, 2H), 7.43 (br s, 1H), 8.29-8.33 (m, 2H); 13 C NMR (100 MHz, CDCl 3 ) 14.3, 29.0, 58.0, 61.5, 104.5, 110.6, 111.5, 116.5, 116.7, 116.8, 116.9, 118.8, 119.8, 122.4, 122.8 (d, J = 38.8 Hz), 123.3, 125.4, 125.6, 126.4, 126.8 (d, J = 17.5 Hz), 127.7, 127.8, 130.3, 130.7 (d, J = 3.8 Hz), 133.3 ( 2), 133.4 ( 2), 136.3, 143.6, 143.8, 162.9 (s, d, J = 246.3 Hz), 174.0; 19 F NMR (470 MHz, CDCl 3 ) -113.1; MS (ES+, Ar) m/z (rel intensity) 519 (MH +, 40), 518 (M +, 38), 517 ([M-H] +, 100); HRMS (ES+) calcd for C 33 H 28 FN 2 O 3 (MH + ) 519.2078, found 519.2071. 7. Scale up (1 mmol) synthesis of 10-(3-methoxyphenyl)-3-(pyrrolidin-1-yl)phenanthren-9-ol) (6a). To a stirred solution of naphthoquinone 3a (334 mg, 1.0 mmol, 1 equiv) and pyrrolidine (71 mg, 0.08 ml, 1.0 mmol, 1 equiv) in toluene (6 ml), catalytic amount of p-tsoh (50 mg, 0.3 mmol, 30 mol %) was added and the resulting reaction mixture was subjected to reflux. After the completion of reaction (4 h), the reaction mixture was concentrated in vacuo and the residue was purified by silica gel column chromatography by gradient elution with ethyl acetate/petroleum ether (5:95) and the 6a was isolated in 79% (291 mg) yield. 8. One-pot synthesis of selected phenanthrenols 6 (see Scheme 5, main text). To a stirred solution of sulfonyl phthalide 1 (301 mg, 1.1 mmol, 1.1 equiv) in THF (9 ml), Cs 2 CO 3 (489 mg, 1.5 mmol, 1.5 equiv) was added. After 5 min, the RC adduct of nitroalkene 2 (1.0 mmol, 1 equiv) was added and the reaction mixture was stirred until the completion of reaction. The solvent was removed in vacuo and the crude residue was directly subjected for the next step. The crude was dissolved in toluene (6 ml) and to this amine (1.0 mmol, 1 equiv) and catalytic amount of p-tsoh (50 mg, 0.3 mmol, 30 mol %) were added and the resulting reaction mixture was subjected to reflux. After the completion of the reaction, the reaction mixture was concentrated in vacuo and the residue was purified by silica gel column chromatography by gradient elution with ethyl acetate/petroleum ether (2:98 to 9:91) to afford pure phenathrenol 6. 9. General procedure for the synthesis of benzoquinolinols 7. To a stirred solution of naphthoquinone 3 (0.12 mmol, 1 equiv) in acetic acid (2 ml), ammonium acetate (93 mg, 1.2 mmol, 10 equiv) was added and the resulting reaction mixture was heated to reflux. After the completion of reaction (monitored by TLC), the reaction mixture was diluted with chloroform (15 ml) and washed with sat aq NaHCO 3 (3 5 ml). The combined organic layer was dried over Na 2 SO 4 and concentrated in vacuo. The crude product was purified by silica gel column chromatography by gradient elution with ethyl acetate/petroleum ether (2:98 to 7:93). 5-(4-Methoxyphenyl)-2-methylbenzo[h]quinolin-6-ol (7a) Light yellow solid; Yield 34 mg, 89%; mp 187-189 o C; IR (KBr, cm - 1 ) 3442 (br w), 2916 (vs), 2848 (s), 1594 (w), 1510 (w), 1461 (w), 1240 (w), 1172 (w), 1028 (w), 736 (m); 1 H NMR (500 MHz, CDCl 3 ) 11
2.79 (s, 3H), 3.92 (s, 3H), 5.59 (br s, 1H), 7.13 (d, J = 8.4 Hz, 2H), 7.23 (d, J = 8.3 Hz, 1H), 7.37 (d, J = 8.4 Hz, 2H), 7.62 (d, J = 8.3 Hz, 1H), 7.72-7.78 (m, 2H), 8.35 (dd, J = 7.6, 1.5 Hz, 1H), 9.38 (d, J = 7.6 Hz, 1H); 13 C NMR (125 MHz, CDCl 3 ) 25.1, 55.6, 115.4, 115.5, 122.4, 122.5, 124.6, 125.3, 125.4, 126.5, 127.5, 128.2, 131.9, 132.7, 133.1, 142.3, 146.2, 154.9, 160.1; MS (ES+, Ar) m/z (rel intensity) 317 ([M+2] +, 20), 316 (MH +, 100), 301 (3); HRMS (ES+) calcd for C 21 H 18 NO 2 (MH + ) 316.1332, found 316.1329. 2-Methyl-5-phenylbenzo[h]quinolin-6-ol (7b) Light yellow solid; Yield 29 mg, 85%; mp 180-182 o C; IR (KBr, cm -1 ) 3538 (w), 2955 (m), 2924 (s), 1594 (s), 1497 (m), 1395 (m), 1217 (m), 1070 (m), 758 (vs), 738 (s); 1 H NMR (500 MHz, CDCl 3 ) 2.80 (s, 3H), 5.55 (br s, 1H), 7.23 (d, J = 8.4 Hz, 1H), 7.45-7.48 (m, 2H), 7.55 (tt, J = 6.8, 1.3 Hz, 1H), 7.61-7.64 (m, 3H), 7.73-7.79 (m, 2H), 8.36 (dd, J = 7.9, 1.2 Hz, 1H), 9.39 (d, J = 7.9 Hz, 1H); 13 C NMR (125 MHz, CDCl 3 ) 25.1, 115.9, 122.4, 122.6, 124.7, 125.0, 126.6, 127.6, 128.3, 129.0, 130.1, 131.6, 133.2, 133.8, 142.1, 142.2, 146.0, 154.9; MS (ES+, Ar) m/z (rel intensity) 287 ([M+2] +, 20), 286 (MH +, 100); HRMS (ES+) calcd for C 20 H 16 NO (MH + ) 286.1226, found 286.1224. 5-(4-Fluorophenyl)-2-methylbenzo[h]quinolin-6-ol (7c) Light yellow solid; Yield 34 mg, 94%; mp 159-161 o C; IR (KBr, cm -1 ) 3535 (br m), 2926 (m), 2854 (w), 1598 (s), 1519 (m), 1505 (m), 1398 (m), 1290 (m), 1222 (vs), 853 (m), 832 (m), 771 (vvs); 1 H NMR (500 MHz, CDCl 3 ) 2.79 (s, 3H), 5.59 (br s, 1H), 7.23 (d, J = 8.4 Hz, 1H), 7.29 (t, J = 8.6 Hz, 2H), 7.42 (dd, J = 8.5, 5.4 Hz, 2H), 7.54 (d, J = 8.4 Hz, 1H), 7.73-7.79 (m, 2H), 8.35 (dd, J = 8.5, 1.7 Hz, 1H), 9.37 (d, J = 8.5 Hz, 1H); 13 C NMR (125 MHz, CDCl 3 ) 25.1, 114.8, 117.1 (d, J = 21.3 Hz), 122.4, 122.5, 124.7, 125.0, 126.5, 127.7, 128.3, 129.6 (d, J = 2.5 Hz), 132.0, 132.8, 133.4 (d, J = 7.5 Hz), 142.3, 146.2, 155.1, 163.1 (d, J = 247.5 Hz); 19 F NMR (470 MHz, CDCl 3 ) -112.4; MS (ES+, Ar) m/z (rel intensity) 305 ([M + 2] +, 15), 304 (MH +, 100); HRMS (ES+) calcd for C 20 H 15 FNO (MH + ) 304.1132, found 304.1127. 5-(4-Chlorophenyl)-2-methylbenzo[h]quinolin-6-ol (7d) Light yellow solid; Yield 35 mg, 91%; mp 214-215 o C; IR (KBr, cm -1 ) 3331 (br m), 2917 (s), 2851 (m), 1588 (s), 1487 (m), 1395 (s), 1208 (m), 1178 (s), 1065 (s), 841 (m), 825 (m), 772 (m), 732 (vs); 1 H NMR (500 MHz, CDCl 3 ) 2.79 (s, 3H), 5.56 (br s, 1H), 7.22 (d, J = 8.4 Hz, 1H), 7.39 (d, J = 8.5 Hz, 2H), 7.55 (d, J = 8.4 Hz, 1H), 7.56 (d, J = 8.5 Hz, 2H), 7.72-7.79 (m, 2H), 8.34-8.37 (m, 1H), 9.37 (d, J = 7.7 Hz, 1H); 13 C NMR (125 MHz, CDCl 3 ) 25.1, 114.7, 122.5, 122.6, 124.7, 126.5, 127.8, 128.3, 130.2, 132.1, 132.3, 132.8, 133.0, 133.1, 135.1, 142.3, 146.1, 155.2; MS (ES+, Ar) m/z (rel intensity) 321 ([M+2] +, 20), 320 (MH +, 100); HRMS (ES+) calcd for C 20 H 15 ClNO (MH + ) 320.0837, found 320.0842; Selected X-ray data: C 20 H 14 ClNO, M = 319.77, Monoclinic, space group P 1 21/c 1, a = 8.1638(8) Å, b = 14.3230(11) Å, c = 13.4195(10) Å, α = 90, β = 107.745(9), γ = 90, V = 1494.5(2) Å 3, Dc = 1.421 Mg/m 3, Z = 4, F(000) = 664, λ = 0.71073 Å, µ = 0.259 mm -1, total/ unique reflections = 8424/4235 [R(int) = 0.0564], T = 293(2) K, θ range = 12
2.14 to 31.16, Final R [I >2 σ (I)]: R1 = 0.0650, wr2 = 0.1647; R (all data): R1 = R1 = 0.1191, wr2 = 0.2394. 2-Methyl-5-(naphthalen-1-yl)benzo[h]quinolin-6-ol (7e) Light yellow solid; Yield 31 mg, 78%; mp 199-201 o C; IR (KBr, cm -1 ) 3327 (br m), 2917 (m), 2851 (m), 1587 (m), 1496 (m), 1409 (s), 1394 (s), 1214 (m), 1177 (m), 1119 (m), 797 (m), 769 (vs); 1 H NMR (500 MHz, CDCl 3 ) 2.78 (s, 3H), 5.39 (br s, 1H), 7.11 (d, J = 8.4 Hz, 1H), 7.29 (d, J = 8.4 Hz, 1H), 7.34 (td, J = 6.9, 1.1 Hz, 1H), 7.44 (d, J = 8.3 Hz, 1H), 7.54 (td, J = 6.9, 1.1 Hz, 1H), 7.60 (dd, J = 6.9, 1.1 Hz, 1H), 7.68 (dd, J = 6.9, 1.1 Hz, 1H), 7.78 (td, J = 8.1, 1.5 Hz, 1H), 7.82 (td, J = 8.1, 1.5 Hz, 1H), 7.99 (d, J = 8.3 Hz, 1H), 8.06 (d, J = 8.3 Hz, 1H), 8.39 (dd, J = 8.2, 1.0 Hz, 1H), 9.44 (dd, J = 8.2, 1.0 Hz, 1H); 13 C NMR (125 MHz, CDCl 3 ) 25.2, 113.7, 122.5, 122.7, 124.7, 125.4, 125.9, 126.2, 126.6, 126.9, 127.2, 127.7, 128.2, 128.8, 129.7, 130.1, 131.1, 132.4, 133.1, 133.3, 134.4, 142.4, 146.8, 155.1; MS (ES+, Ar) m/z (rel intensity) 337 ([M + 2] +, 50), 336 (MH +, 100); HRMS (ES+) calcd for C 24 H 18 NO (MH + ) 336.1383, found 336.1380. 5-(Furan-2-yl)-2-methylbenzo[h]quinolin-6-ol (7f) Brown oil; Yield 23 mg, 70%; IR (neat, cm -1 ) 3506 (w), 2926 (m), 2854 (w), 1623 (w), 1595 (m), 1520 (w), 1502 (m), 1420 (w), 1395 (m), 1265 (w), 1220 (m), 1069 (m), 1014 (m), 910 (m), 828 (m), 755 (vs), 737 (vs); 1 H NMR (500 MHz, CDCl 3 ) 2.79 (s, 3H), 6.69 (dd, J = 3.2, 2.0 Hz, 1H), 6.73 (d, J = 3.2 Hz, 1H), 6.92 (d, J = 2.0 Hz, 1H), 7.31 (d, J = 8.4 Hz, 1H), 7.72-7.74 (m, 2H), 7.78 (t, J = 8.1 Hz, 1H), 8.08 (d, J = 8.4 Hz, 1H), 8.39 (d, J = 8.1 Hz, 1H), 9.33 (d, J = 8.1 Hz, 1H); 13 C NMR (125 MHz, CDCl 3 ) 25.1, 105.2, 111.8 ( 2), 122.6, 122.9, 123.7, 124.6, 126.5, 128.2, 128.3, 132.7, 132.8, 142.4, 143.5, 148.3, 148.5, 155.3; MS (ES+, Ar) m/z (rel intensity) 277 ([M+2] +, 30), 276 (MH +, 100); HRMS (ES+) calcd for C 18 H 14 NO 2 (MH + ) 276.1019, found 276.1019. 10. Scale up (1 mmol) synthesis of 5-(4-Methoxyphenyl)-2-methylbenzo[h]quinolin-6-ol (7a). To a stirred solution of naphthoquinone 3b (334 mg, 1.0 mmol, 1 equiv) in acetic acid (5 ml), ammonium acetate (770 mg, 10 mmol, 10 equiv) was added and the resulting reaction mixture was heated to reflux. After the completion of reaction (2 h, monitored by TLC), the reaction mixture was diluted with chloroform (40 ml) and washed with sat aq NaHCO 3 (3 10 ml). The combined organic layer was dried over Na 2 SO 4 and concentrated in vacuo. The crude product 7a was purified by silica gel column chromatography by gradient elution with ethyl acetate/petroleum ether (6:94) and isolated in 89% (280 mg) yield. 11. One-pot synthesis of selected phenanthrenols 6 (see Scheme 5, main text). To a stirred solution of sulfonyl phthalide 1 (301 mg, 1.1 mmol, 1.1 equiv) in THF (9 ml), Cs 2 CO 3 (489 mg, 1.5 mmol, 1.5 equiv) was added. After 5 min, the RC adduct of nitroalkene 2 (1.0 mmol, 1 equiv) was added and the reaction mixture was stirred until the completion of reaction. The solvent was removed in vacuo and the crude residue was directly subjected for the next step. To the crude residue, acetic acid (5 ml) and ammonium acetate (770 mg, 10 mmol, 10 equiv) were added and the resulting reaction mixture was heated to reflux. After the completion of reaction (monitored by TLC), the reaction mixture was diluted with chloroform (40 ml) and washed with sat aq NaHCO 3 (3 10 ml). The organic layer was dried over Na 2 SO 4 and concentrated in vacuo. The crude 13
residue was purified by silica gel column chromatography by gradient elution with ethyl acetate/petroleum ether (2:98 to 7:93) to afford pure benzoquinoline 7. 12. 4-(9-((4-Bromobenzyl)oxy)-10-(4-fluorophenyl)phenanthren-3-yl)morpholine (8) To a stirred solution of 4-(9-((4-bromobenzyl)oxy)-10-(4-fluorophenyl)phenanthren-3- yl)morpholine (6c, 160 mg, 0.43 mmol) in dry DMF (3 ml) were added K 2 CO 3 (178 mg, 1.29 mmol, 3 equiv) and p-bromobenzyl bromide (162 mg, 0.645 mmol, 1.5 equiv) at room temperature under nitrogen atmosphere and the reaction mixture was stirred for 5 h. After the completion of the reaction (monitored by TLC), the reaction mixture was filtered through a pad of Celite. The filtrate was neutrallized with 3 M HCl (2 ml) and ether (10 ml) was added. The organic layer was separated, and the aqueous layer was extracted twice with ether (10 3 ml). The combined organic layers were washed with water (2 10 ml), saturated aq NaHCO 3 (15 ml) and brine (10 ml), dried over Na 2 SO 4, and filtered. The filtrate was concentrated in vacuo and the resulting residue was purified by flash column chromatography on silica gel (pet ether/ethyl acetate 10-15%) to afford benzyl ether 8 as a light yellow solid. Light yellow solid; 200 mg, 86%; mp 209-211 C; IR (neat, cm -1 ) 2952 (w), 2856 (m), 2827 (w), 1614 (s), 1505 (s), 1437 (m), 1233 (vs), 1122 (s), 1069 (s), 945 (s), 827 (s), 765 (vs); 1 H NMR (CDCl 3, 500 MHz) δ 3.35 (t, J = 4.6 Hz, 4H), 3.95 (t, J = 4.6 Hz, 4H), 4.58 (s, 2H), 6.95 (d, J = 8.2 Hz, 2H), 7.19-7.23 (m, 3H), 7.41-7.46 (m, 4H), 7.52 (d, J = 9.0 Hz, 1H), 7.67 (m, 2H), 8.10 (d, J = 1.8 Hz, 1H), 8.23 (d, J = 7.6 Hz, 1H), 8.69 (d, J = 7.9 Hz, 1H); 13 C NMR (CDCl 3, 125 MHz) δ 49.8, 67.1, 74.9, 107.2, 115.4 (d, J = 21.0 Hz), 117.9, 122.1, 123.0, 123.2, 126.4, 126.9, 127.2, 127.6, 127.7, 128.3, 129.5, 129.9, 131.1, 131.6, 132.4 (d, J = 3.0 Hz), 132.9 (d, J = 8.0 Hz), 136.2, 148.3, 149.5, 162.4 (d, J = 245.0 Hz); 19 F NMR (376 MHz, CDCl 3 ) δ -114.7; HRMS calcd for C 31 H 26 BrFNO 2 (MH + ) 542.1125, found 542.1117; Selected X-ray data: C 248 H 200 Br 8 F 8 N 8 O 16, M = 4339.43, triclinic, space group P-1, a = 15.5990(3) Å, b = 18.6900(5) Å, c = 19.2605(5) Å, α = 70.341(2), β = 87.900(2), γ = 67.582(2), V = 67.582(2) Å 3, Dc = 1.482 g/m 3, Z = 1, F(000) = 2224.0, λ = 0.71073Å, µ = 1.729 mm -1, total/ unique reflections = 71213/16991 [R int = 0.0569, R sigma = 0.0453], T = 150.15 K, θ range = 3.924 to 49.996, Final R [I >2 σ (I)]: R 1 = 0.0389, wr 2 = 0.0883; R (all data): R 1 = 0.0527, wr 2 = 0.0958. III. References (1) Sakulsombat, M.; Angelin, M.; Ramström, O. Tetrahedron Lett. 2010, 51, 75. (2) (a) Dadwal, M.; Mohan, R.; Panda, D.; Mobin, S. M.; Namboothiri, I. N. N. Chem. Commun. 2006, 338. (b) Deb, I.; Shanbhag, P.; Mobin, S. M.; Namboothiri, I. N. N. Eur. J. Org. Chem. 2009, 4091. 14