Carbamate-stabilized anions of 2-azabicyclo[2.1.1]hexanes

The regiochemical outcomes for s-BuLi/TMEDA deprotonations of N-Boc-2-azabicyclo[2.1.1]hexanes had been shown to be temperature dependent. Computational methods have been applied to advance understanding of the complexes that the reagents form, the character of the deprotonations, and hence the experimentally observed regiochemical biases. The tertiary anion is formed more readily than the secondary anion and is also the more stable anion. Computations for the enthalpy of proton abstraction from the analogous N-methoxycarbonyl structure also indicate greater stability for the tertiary carbamate anion.

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