Natural-Products-Inspired Use of the gem-Dimethyl Group in Medicinal Chemistry

The gem-dimethyl moiety is a structural feature frequently found in many natural products of clinical interest, including, but not limited to, taxanes, epothilones, statins, retinoids, di-/triterpenes, noviose deoxysugar, and antibiotics derived from β-lactams, macrolides, and aminocoumarins. Inspired by this time-tested moiety, medicinal chemists have widely explored its use in developing bioactive molecules because of the possibility to (1) increase target engagement, potency, and selectivity through van der Waals interactions and entropically favorable restriction to a bioactive conformation, (2) mitigate toxicity, (3) obtain superior DMPK profile, (4) modulate the pKa of nearby functionality, (5) induce symmetry into a monomethyl substituted chiral center, and (6) apply the Thorpe–Ingold conformational effect in an o-hydroxydihydrocinnamic acid based prodrug design. The aim of this Perspective is to illustrate how medicinal chemists have elegantly employed the gem-dimethyl group to obtain clinically useful drugs and to provide synthetic methods to install a gem-dimethyl group.