ORGANIC REACTIONS AND SYNTHETIC ROUTES (HL)
Organic reactions are organized according to:
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Type of reaction (what happens)
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Mechanism of the reaction (how it happens)
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Describe according to electrophilic and nucleophilic behavior!
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Homolytic fission – Even distribution of electrons resulting inn formation of free-radicals (curly arrow)
Heterolytic fission – Uneven distribution of electrons resulting in formation of ions (fish hook)
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Nucleophiles are reactants that are electron rich do they are attracted to electron deficient atoms.
- They act as Lewis bases (electron pair donors)
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Electrophiles are electron deficient and accept electron pairs from a nucleophile.
- They act as Lewis acids (electron pair acceptors)
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LEAVING GROUP: The halogen that becomes detached in the reaction
- One step concerted reaction INVERSION!!
DRAWING MECHANISM
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Curly arrow from lone pair/negative charge of nucleophile to carbon atom.
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Curly arrow shows leaving group (originates at bond between carbon and halogen)
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Show partial bond in unstable transition state
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Transition state enclosed in square brackets and a single negative charge
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Formation of product and end leaving group must be shown
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SN2 reaction is stereospecific
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3D arrangement of reactants determines 3D arrangement of product
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Bond formation happens before bond cleavage in transition state
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DRAWING MECHANISM (SN2)
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Curly arrow shows the halogen leaving group
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Positive charge on the center carbon atom shows creation of carbocation
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Curly arrow from nucleophile to carbon atom
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Formation of product and leaving group must be shown
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SN1 – Protic solvent (polar)
SN2 – Aprotic solvent (non-polar)
Types of Organic Reactions
