List of used abbreviations - RosDok - Universität Rostock

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General Introduction Because sulfur is directly below oxygen in the periodic table, these elements have similar electron configurations. As a result, sulfur forms many compounds that are analogs of oxygen compounds. There are four principal differences between the chemistry of sulfur and oxygen: O=O double bonds are much stronger than S=S double bonds. S-S single bonds are almost twice as strong as O-O single bonds. Sulfur (EN = 2.58) is much less electronegative than oxygen (EN = 3.44). Sulfur can expand its valence shell to hold more than eight electrons, but oxygen cannot. The C-S bond is both longer, because S is larger, and weaker than C-C bonds. Selected bond lengths in sulfur compounds are 183 pm for the S-C single bond in methanethiol and 173 pm in thiophene. 1 Some applications of sulphur can be summarized as follows: Sulfur is mostly used for the production of sulfuric acid, H2SO4. Most sulfur is mined using the Frasch process. Sulfur is, for example, used for the synthesis of sulfuric acid which is the most abundantly produced chemical in the United States and manufactured by the Contact process. Most (about 70%) of the sulfuric acid produced in the world is used in the fertilizer industry. Sulfuric acid can act as a strong acid, as a dehydrating agent, and as an oxidizing agent. Although there is no known dietary requirement for inorganic sulfur, it is an essential element for all animal species as they all require the sulfur-containing amino acid methionine. There are three predominant forms of organic sulfur in animals and 6
humans: 1) the thiomethyl of methionine residues in proteins; 2) the disulfides present in proteins; and 3) sulfates present in glycosaminoglycans, steroids, and many xenobiotic metabolites. Thus, sulfur is an important constituent of amino acids, proteins, enzymes, vitamins and other biomolecules. Unlike mammalian species, plants can use inorganic sulfur for the biosynthesis of methionine from which are synthesized all the other important bioorganic sulfur compounds. Hence, sulfur deficiency occurs mainly when plants are grown in sulfur-depleted soils and when humans and animals consume low-protein diets. In recent time, the increasing prevalence of refining petroleum and the conversion of sulfur-containing metal salts and minerals into the free metals have a large impact on the balance of sulfur in the environment. Sulfur toxicity is associated mainly with high levels of volatile substances in the environment. Sulfur dioxide (SO2), a major air pollutant, may adversely affect animal and human health by causing bronchitis, bronchoconstriction, and increased pulmonary resistance. Most organic sulfur compounds in the environment are naturally occurring, as a consequence of the fact that sulfur is essential for life and two amino acids contain this element. Organosulfur compounds are often associated with foul odours, but ironically many of the sweetest compounds known are organosulfur derivatives. Nature abounds with organosulfur compounds—sulfur is essential for life. Two of the 20 common amino acids are organosulfur compounds. Fossil fuels, coal, petroleum, and natural gas, which are derived from ancient organisms, necessarily contain organosulfur compounds, the removal of which is a major focus of oil refineries. Not all organosulfur compounds are foul-smelling pollutants. Compounds like allicin (chart 1) and ajoene (chart 2) are responsible for the odor of garlic, and lenthionine contributes to the flavor of shiitake mushrooms. Many of these natural products also 7
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: RCM Ring Closing Metathesis TBAI Te
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 and 24: l a u 4-FC6H4 H Me H 40 m a v 4-FC6
Page 25 and 26: Table 2. Synthesis of thioxanthones
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)
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OCH3), 7.08-7.17 (m, 7H, Ar); 13 C
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(w), 750 (s), 732 (s), 688 (s), 650
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35 Cl 35 Cl, 100), 359 (26), 357 (3
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2924 (w), 2853 (w), 1728 (s), 1712
Page 85 and 86:
Me 3-Hydroxy-5-(4-methylphenylsulfa
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Et 3-Hydroxy-5-(4-ethylphenylsulfan
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(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
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20. For a review of [3+3] cyclizati
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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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