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waterdemon (3810)

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SN₁ Reaction :

1)First order kinetics

2)Two or more steps with a reactive intermediate.

3)Sensitive to electronic effects.

4)side products possible due to rearrangement.

5)Competes with E1.

6)Substrate preferences 3⁰>2⁰>1⁰>Me

7)Typically 3⁰ halides are the best.

8)requies polar protic solvents.

9)Usually the solvent is the nucleuphile.

SN₂ :

1)Second order kinetics.

2)single elementary steps , no reactive intermediate ; a

single transition state.

3)No rearrangement possible.

4)Competes with E2.

5)Substrate preferences : Me>1⁰>2⁰>3⁰

6)Typically 1⁰ halides are the best.

7)Much better in aprotic solvents (eg : DMF ).

8)Strong nucleuphile in high concentration favour it.

E1 :

1)Two step , cation intermediate.

2)Competes with SN1.

3)Favoured in 3⁰ substrates.

4)favoured by polar protic solvents.

5)Base strength is irrelevant.

E2 :

1)Single step , no intermediate.

2)Competes with SN2.

3)Trans co-planar , Trans-diaxial.

4)Suspectible to steric effects.

5)Favoured in less polar solvent.

6)Favoured by strong and hindred bases.

7)Favoured by increased Temperature.

Hope all of you find it useful.

Cheers !!!!!!!!!!!!

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