HOAÙ HOÏC HÖÕU CÔ

1. HOAÙ HOÏC HÖÕU CÔ CHÖÔNG 6 Alkanes Organic Chemistry

2. GIÔÙI THIEÄU MOÂN HOÏC • : HOÙA HOÏC HÖÕU CÔ • (ORGANIC CHEMISTRY) • Soá tín chæ: 3 (3.1.6) • Maõ soá moân hoïc: 606010 • Noäi dung toùm taét moân hoïc: • Lieân keát- Caáu taïo-caáu truùc hôïp chaát höõu cô • Phaûn öùng vaø cô cheá phaûn öùng höõu cô • Caùc phöông phaùp cô baûn toång hôïp caùc hôïp chaát höõu cô • Tính chaát lyù hoùa caùc hôïp chaát höõu cô • ÖÙng duïng: Hôïp chaát maøu, hôùp chaát coù höông, chaát hoaït ñoäng beà maët, chaát noå, chaát dieät khuaån-coân truøng, chaát kích thích taêng tröôûng….

3. Unbranched Alkanes • “Straight-chain” alkanes have a zig-zag orientation when they are in their most straight orientation

4. Branched Alkanes • Branched alkanes have at least one carbon which is attached to more than two other carbons

5. Physical Properties • Boiling points of unbranched alkanes increase smoothly with number of carbons • CH4-C4H10: gazes • Melting points roughly increase with number of carbons • C5H12-C17H36: liquids • Low polarity • Insoluble in water • Soluble in non-polar solvents

6. Physical Properties • The boiling point increases with the length of the chain

7. Structural Isomers • Constitutional isomers have the same molecular formula but different connectivity of atoms

8. IUPAC Rules for Alkanes and Alkyl Halides • Select the longest continuous chain Basic name • Number the carbons form the end nearest the first branch Numbering • Locate substituents on the main chain Location If two substituents on the same carbon, use the number twice • Identify substituents Identification if more than one use “di”, “tri”, “tetra”,… • Put substituents in alphabetical order • Separate numbers from letters using dashes and place the basic name at the end.

9. DANH PHAÙP http://www.acdlabs.com/iupac/nomenclature/

10. Radicals • CH3- methyl (Me) • CH3-CH2- ethyl (Et) • CH3-CH2-CH2- n-propyl (nPr) • (CH3)2-CH- iso-propyl (iPr) • CH3-CH2-CH2-CH2- n-butyl (nBu) • (CH3)2-CH-CH2- iso-butyl (iBu) • (CH3)3-C- tert-butyl (tBu) • C6H5- phenyl (Ph)

11. DANH PHAÙP

12. DANH PHAÙP

13. Alkanes

14. DANH PHAÙP

15. DANH PHAÙP

16. LAI HOÁ sp3

17. Nobel prize 1969 • Sir Derek Barton (UK, 1918-1998) • Odd Hassel (Norway, 1897-1981) • for their contributions to the development of the concept of conformation and its application in chemistry"

18. Sir Derek Barton • Nobel Lecture starting with this citation:

19. Stereoisomers • Conformers • Isomers resulting from the free rotation of a single bond • Ethane: staggered conformation (C-H bonds on adjacent carbons as far apart from each other as possible) The drawing to the right is called a Newman projection • eclipsed conformation: all C-H bonds on adjacent carbons directly on top of each other

20. The Newman Representation

21. The Newman Representation • Staggered and eclipsed Staggered Eclipsed

22. 3D Formulas

23. The Torsional Strains Staggered: most stable Eclipsed: least stable

24. Ethane conformation • the staggered conformation is more stable than eclipsed by 12 kJ mol-1

25. ÑOÀNG PHAÂN CAÁU DAÏNG

26. ÑOÀNG PHAÂN CAÁU DAÏNG

27. Butane • Anti most stable • Fully eclipsed most unstable

28. Butane • Gauche less stable than anti • Eclipsed less unstable than fully eclipsed

29. Butane

30. Butane

31. ÑOÀNG PHAÂN CAÁU DAÏNG

32. ÑOÀNG PHAÂN CAÁU DAÏNG

33. Preparation of Alkanes • Catalytic hydrogenation of alkenes and alkynes

34. Preparation of Alkanes

35. Preparation of Alkanes

36. Preparation of Alkanes

37. Preparation of Alkanes • The Kolbe reaction is the electrosynthesis of hydrocarbons via electrooxidation of carboxylic acids.

38. Preparation of Alkanes

39. Preparation of Alkanes

40. Reduction/Oxidation • Reduction: gain of hydrogen, loss of oxygen, … • Level of oxidation decreases • Oxidation: gain of oxygen, loss of hydrogen, … • Level of oxidation increases • Hydrogenation: reduction of alkenes and alkynes

41. Syn Addition in Heterogeneous Catalysis • hydrogen and alkene adsorbed to the catalyst surface

42. Syn Addition • Both hydrogens add to the same face of the alkene (syn addition)

43. Examples • 1,2-dimethylcyclohexene

44. Reduction of Alkyl Halides • With metals

45. Paul Sabatier (1854-1941) • Nobel Prize 1912 • "for his method of hydrogenating organic compounds in the presence of finely disintegrated metals whereby the progress of organic chemistry has been greatly advanced in recent years" • University of Toulouse, France

46. Victor Grignard • Nobel prize 1912 • "for the discovery of the so-called Grignard reagent, which in recent years has greatly advanced the progress of organic chemistry" • University of Nancy, France • Ph. Barbier, University of Lyon, France • Barbier reaction

47. Grignard Reagents • Grignard reagent preparation • Reaction of organic halides with magnesium turnings in ether (DRY ether) • Killed with water: form alkanes

48. Grignard Reagents • Strongly react with water • Grignard reagents behave as if they were carbanions and they are therefore very strong bases • R rich in electron

49. Grignard Reagents • Formally: conversion of halides to hydrogen • The Grignard reaction: addition of Grignard reagents to carbonyls

50. Elias J. Corey • Nobel Prize 1990 • "for his development of the theory and methodology of organic synthesis" • Harvard University, USA • Many Corey reactions… • (Corey-Winter, Corey-Chakovsky, Corey-Bakshi-Shibata, Corey-Fuchs, Corey-Kim, …) • … and reagents • PDC, PCC, …