Bicyclo[1.1.1]pentan-1-amine as Bioisostere of Benzene Ring

Baran et al. have reported a scalable synethesis of bicyclo[1.1.1]pentan-1-amine hydrochloride (2) from 1,1-dibromo-2,2-bis(chloromethyl)cyclopropane (1). The small strained bicyclo[1.1.1]pentane strained scaffold is a functionalized bioisostere of a benzene ring and tert-butyl group, and has applications in medicinal chemistry and drug discovery though it’s superior metabolic stabilities, membrane permeability and aqueous solubility compared to phenyl rings. Baran et al. have also have included 1 into the synthesis of various bicyclo[1.1.1]pentane units. This synthetic approach is expected to be applied for the structural optimization of drug candidates.