Enantioconvergent catalysis

Enantioconvergent catalysis

An enantioconvergent catalytic process has the potential to convert a racemic starting material to a single highly enantioenriched product with a maximum yield of 100%. Three mechanistically distinct approaches to effecting enantioconvergent catalysis are identified, and recent examples of each are highlighted. These processes are compared to related, non-enantioconvergent methods.

Enantioconvergent Synthesis of Functionalized γ-Butyrolactones via (3 + 2)-Annulation

A dynamic kinetic resolution of β-halo α-keto esters in an asymmetric homoenolate reaction is described. A chiral N-hetereocyclic carbene catalyzes the a(3) → d(3)-umpolung addition of α,β-enals to racemic α-keto esters, forming γ-butyrolactones with three contiguous stereocenters. The addition occurs with high regio-, diastereo-, and enantiocontrol. This methodology constitutes an intermolecul...

Homogeneous Catalysis Homogeneous Catalysis

One-Pot Deracemization of sec-Alcohols: Enantioconvergent Enzymatic Hydrolysis of Alkyl Sulfates Using Stereocomplementary Sulfatases**

Given the fact that the theoretically possible number of racemates is larger than that of symmetric prochiral or meso compounds, the development of deracemization methods, which yield a single stereoisomer from a racemate is an important topic. Enantioconvergent processes are based on the transformation of a pair of enantiomers through opposite stereochemical pathways affecting retention and in...

Palladium-catalyzed decarboxylative allylic alkylation of diastereomeric β-ketoesters.

The palladium-catalyzed decarboxylative allylic alkylation of diastereomeric β-ketoesters derived from 4-tert-butylcyclohexanone is described. These experiments were performed to elucidate our understanding of stereoablative enantioconvergent catalysis. A detailed analysis of the product distribution, including stereochemical outcome of the products, is included. These studies also reveal an in...