Tertiary alcohols are versatile building blocks in organic synthesis and serve as important platform molecules for diverse organic transformations. Asymmetric functionalization and transformation of tertiary alcohols can provide expedient access to stereocenters and is highly coveted. In the recent decades, chiral phosphoric acid (CPA) has been widely used to catalyze these asymmetric reactions. This thesis describes two CPA-catalyzed asymmetric transformations of tertiary alcohols.

In chapter 1, a highly efficient organocatalytic asymmetric reduction of tertiary alcohols is described. With the optimal combination of a CPA catalyst and an organic hydride source, a wide range of triarylmethanols smoothly reacted to efficiently afford enantioenriched triarylmethanes. This methodology achi...[ Read more ]

Tertiary alcohols are versatile building blocks in organic synthesis and serve as important platform molecules for diverse organic transformations. Asymmetric functionalization and transformation of tertiary alcohols can provide expedient access to stereocenters and is highly coveted. In the recent decades, chiral phosphoric acid (CPA) has been widely used to catalyze these asymmetric reactions. This thesis describes two CPA-catalyzed asymmetric transformations of tertiary alcohols.

In chapter 1, a highly efficient organocatalytic asymmetric reduction of tertiary alcohols is described. With the optimal combination of a CPA catalyst and an organic hydride source, a wide range of triarylmethanols smoothly reacted to efficiently afford enantioenriched triarylmethanes. This methodology achieved a challenging discrimination between an aryl ring and a heteroaryl ring without the installation of a directing group or the manipulation of electronic bias between the two rings.

In chapter 2, an electricity-driven asymmetric semi-pinacol rearrangement is described. A series of tertiary allylic alcohols underwent asymmetric bromination/semi-pinacol rearrangement to afford enantioenriched β-bromo ketones. The key catalytic species featured the combination of a DABCO-based ammonium salt and a chiral phosphate base decorated with a SPHENOL skeleton designed by the Sun group. The DABCO-based ammonium salt captured the bromine generated via anodic oxidation and the in situ generated insoluble cationic brominating reagent was efficiently extracted into the organic phase by a chiral phosphate base. This chiral brominating ion pair catalyzed the asymmetric semi-pinacol rearrangement