organic chemistry chapter 3 part ii n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Organic Chemistry Chapter 3 Part II PowerPoint Presentation
Download Presentation
Organic Chemistry Chapter 3 Part II

Loading in 2 Seconds...

play fullscreen
1 / 14

Organic Chemistry Chapter 3 Part II - PowerPoint PPT Presentation


  • 83 Views
  • Uploaded on

Organic Chemistry Chapter 3 Part II. Addition to Alkenes - Markovnikov’s rule-. Nanoplasmonic Research Group. Reactions of Alkenes: Addition. Electrophile Literally ‘ ELECTRON ’ lovers: electron-POOR reagents Positive ions or electron-deficient species Nucleophile

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Organic Chemistry Chapter 3 Part II' - naoko


Download Now An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
organic chemistry chapter 3 part ii

Organic ChemistryChapter 3Part II

Addition to Alkenes

- Markovnikov’s rule-

Nanoplasmonic Research Group

reactions of alkenes addition
Reactions of Alkenes: Addition
  • Electrophile
    • Literally ‘ELECTRON’ lovers: electron-POOR reagents
    • Positive ions or electron-deficient species
  • Nucleophile
    • Literally ‘NUCLEUS’ lovers: electron-RICH reagents
    • Donate electrons to an electrophile

E+

+

Nu-

E Nu

markovnikov s rule
Markovnikov’s Rule

The RULE says “The addition of a protic acid such as H-X to an alkene, the acid hydrogen (H) becomes attached to the carbon atom with the greatest number of hydrogens, and the halide (X) group becomes attached to the carbon with the fewest hydrogens”

slide5

Why ???

The stability of Carbocation

(1) Hyperconjugation & (2) Induction

slide6

Mechanism of Electrophilic Addition to Alkenes

The Point is which carbocation is more stable !!

slide7

Hyperconjugation: Alkyl group stabilize carbocation

Induction:

The transmission of charge through a chain of atoms in a molecule by electrostatic induction

types of addition rxns
Types of Addition Rxns
  • Addition of Halogens
  • Addition of Water (hydration)
  • Addition of Acids
hydroboration
Hydroboration
  • Addition of a hydrogen-boron bond to an alkene
  • The Point is that ‘hydrogen’ is more electronegative than ‘boron’
quick reminder
Quick Reminder
  • Alkene Reaction goes through the pathway of the most stable intermediate
  • The more substituents on an electron deficient carbon (carbocation or radical), the greater its stability
additions to conjugated systems
Additions to Conjugated Systems

1,2-addition

1,4-addition

How to Predict ?

Electrophile adds to alkene according to Markovnikov’s rule

Draw possible resonance structures and see how many structures come out

Selectivity may differ depending on the stability of each resonance structure

cycloaddition to conjugated dienes the diels alder reaction
Cycloaddition to Conjugated Dienes- The Diels-Alder Reaction -

Features

  • Concerted as with hydroboration
  • Easy to synthesize a cyclic compound
  • Converts three pi bonds to two sigma bonds & one new pi bond
  • HOMO of diene and LUMO of dienophile
free radical additions
Free-Radical Additions

Initiation by a radical initiator: A radical is created from a non-radical precursor

Chain propagation: A radical reacts with a non-radical to produce a new radical species

Chain termination: Two radicals react with each other to create a non-radical species

Chain branching: see page 102 middle

Features

other reactions with alkenes
Other reactions with alkenes
  • Ozonolysis
    • The oxidation of alkenes with ozone to give carbonyl compounds
    • One can deduce the structure of an unknown alkene