E2/SN2 competition

The E2-Sn2 competition is reasonably easy to evaluate, because basicity (an affinity for H+) is mainly under charge control and nucleophilicity (an affinity for C+) mainly under frontier control. 

Tab. 4.1 Effect of Alkyl Groups in the a Position of the Substrate on the Result of the E2/SN2 Competition...

Fig. 4.19. E2/Sn2 competition in cyclohexanes with poor leaving groups locked in axial (left reaction) or equatorial (right reaction) position. Note that Sn2 reactions involve an N-bound methyl group instead of the N-bound cyclohexyl ring. The reason is the minimization of steric interactions in the Sn2 transition state (cf. "Tendencies and Rules" in Section 2.4.4)...

Fig. 4.18. E2/Sn2 competition in cyclohexanes with poor leaving groups locked in axial (left reaction) or equatorial (right reaction) position.

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