List of used abbreviations - RosDok - Universität Rostock

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Scheme 5. Possible explanation for the regioselective formation of 5e Treatment of 2-(arylthio)benzoates 5b,c,e,f,g,i,j with concentrated sulfuric acid resulted in an intramolecular Friedel-Crafts cyclization to give the thioxanthones 6a-g in excellent yields (Scheme 6, Table 2). The structures of all products were elucidated by spectroscopic methods. The structure of 6f was independently confirmed by X-ray crystal structure analysis (Figure 1). R 1 Me S O R 2 OMe i 20 R 1 Me S R 3 R 3 5b,c,e,f,g,i,j 6a-g Scheme 6. Synthesis of 6a-g. Conditions: i, conc H2SO4 20 °C, 2 h R 2 O
Table 2. Synthesis of thioxanthones 6a-g a Yields of isolated products 5 8 R 1 R 2 R 3 % (6) a b a H Me Me 98 c b H Me Cl 97 e c H nPr H 95 f d Me Me Me 97 g e Me Me Cl 97 i f Et Me Me 95 j g Et Me Cl 96 The TiCl4-mediated cyclization of 3a with 1,1-diacetylcyclopropane (7a) afforded the 2-(phenylthio)benzoate 8a (Scheme 7). During the optimization, the stoichiometry (1.5 equiv. of TiCl4 and of 7a) played an important role. The yields dropped when only 1.0 equiv. of TiCl4 and of 7a were employed. The yield also decreased when an excess of 3a was used. The concentration (30 mL per mmol of 3a) also proved to be an important parameter. A complex mixture was obtained when the reaction was carried out in a highly concentrated solution (following the procedure given for the reaction of 3a with 4-(trimethylsilyloxy)pent-3-en-2-one, vide supra). The formation of 8a can be explained by a domino ′[3+3] cyclization / homo-Michael′ reaction. The TiCl4-mediated attack of the terminal carbon atom of 3a onto 7a gave intermediate E, cyclization via the central carbon atom gave intermediate F, and TiCl4-assisted cleavage of the spirocyclopropane moiety and aromatization led to the formation of the final product 8a. Reactions of acceptor-substituted cyclopropanes have been classified by Danishefsky in terms of ′strictly nucleophilic ring openings′, 21
Page 1 and 2: Synthesis of functionalized 2-(aryl
Page 3 and 4: The ink of the scholar is more holy
Page 5 and 6: Affectionately Dedicated to “All
Page 7 and 8: Table of Contents 03 List of used a
Page 9 and 10: RCM Ring Closing Metathesis TBAI Te
Page 11 and 12: humans: 1) the thiomethyl of methio
Page 13 and 14: Chart 3. Structure of sumatriptan S
Page 15 and 16: disulfide (DADS) and diallyl sulfid
Page 17 and 18: 1. Synthesis of functionalized 2-(a
Page 19 and 20: 3-Arylthio-1-trimethylsilyloxy-1,3-
Page 21 and 22: under kinetic reaction control, by
Page 23: l a u 4-FC6H4 H Me H 40 m a v 4-FC6
Page 27 and 28: 3a O OSiMe 3 O OMe + Me Me Cl 3TiO
Page 29 and 30: Table 3. Synthesis of 8a-x 3 7 8 Ar
Page 31 and 32: Cl + SPh OSiMe 3 3a 9 O OMe O O H i
Page 33 and 34: solution. The use of an excess (1.5
Page 35 and 36: Table 4. Synthesis of 12a-r 3 11 12
Page 37 and 38: 2.3 Conclusion In conclusion, I hav
Page 39 and 40: aromatization). An unseparable 1:2
Page 41 and 42: Table 5. Synthesis of arenes 14a-l
Page 43 and 44: 3.3 Conclusion In conclusion, I hav
Page 45 and 46: Mass Spectroscopy: AMD MS40, AMD 40
Page 47 and 48: 131.0 (ArCH), 132.7, 134.0, 135.9,
Page 49 and 50: (EI, 70 eV): m/z (%): 380 (100), 21
Page 51 and 52: (m), 1490 (m), 1434 (m), 1383 (w),
Page 53 and 54: 15.4, 16.9, 18.9 (CH3), 28.3 (CH2),
Page 55 and 56: (C). IR (neat): ν̃ = 2945 (w), 29
Page 57 and 58: 948 (w) 853 (m), 803 (m), 751 (m),
Page 59 and 60: 135.4, 139.2, 143.8, 146.5, 182.2 (
Page 61 and 62: Me S O Me Ph Br Methyl 4-methyl-5-(
Page 63 and 64: 35 Cl, 37 Cl, 61), 430 (M + , 35 Cl
Page 65 and 66: ArH). 13 C NMR (62 MHz, CDCl3): δ
Page 67 and 68: Me S O Me Me Methyl 4,6-dimethyl-5-
Page 69 and 70: S Methyl 4-methyl-5-(2-bromoethyl)-
Page 71 and 72: (CH2CH3), 33.3 (CH2), 40.1 (CH2), 5
Page 73 and 74: Me 3,4-Dimethyl-2-phenylsulfanyl-be
Page 75 and 76:
Me 3,4-Dimethyl-2-(p-tolylsulfanyl)
Page 77 and 78:
OCH3), 7.08-7.17 (m, 7H, Ar); 13 C
Page 79 and 80:
(w), 750 (s), 732 (s), 688 (s), 650
Page 81 and 82:
35 Cl 35 Cl, 100), 359 (26), 357 (3
Page 83 and 84:
2924 (w), 2853 (w), 1728 (s), 1712
Page 85 and 86:
Me 3-Hydroxy-5-(4-methylphenylsulfa
Page 87 and 88:
Et 3-Hydroxy-5-(4-ethylphenylsulfan
Page 89 and 90:
(13), 264 (13), 262 (36) ,260 (12),
Page 91 and 92:
MS (EI, 70 eV): m/z (%) = 337 (16),
Page 93 and 94:
OH O 5'-Hydroxy-[1,1';3',1'']terphe
Page 95 and 96:
Refrences 1. Handbook of Chemistry
Page 97 and 98:
20. For a review of [3+3] cyclizati
Page 99 and 100:
Nationality Pakistan Place of Birth
Page 101 and 102:
Publications 1. Inam Iqbal, Muhamma
Page 103 and 104:
Tetrahedron 2007, 63, 12562-12575.
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List of used abbreviations - RosDok - Universität Rostock

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