Memory of Chirality in Room Temperature Flow Electrochemical Reactor

Abstract

<p>Many chiral compounds have become of great interest to the pharmaceutical industry as they possess various biological activities. Concurrently, the concept of “memory of chirality” has been proven as a powerful tool in asymmetric synthesis, while flow chemistry has begun its rise as a new enabling technology to add to the ever increasing arsenal of techniques available to the modern day chemist. Here, we have employed a new simple electrochemical microreactor design to oxidise an L-proline derivative at room temperature in continuous flow. Flow performed in microreactors offers up a number of benefits allowing reactions to be performed in a more convenient and safer manner, and even allow electrochemical reactions to take place without a supporting electrolyte due to a very short interelectrode distance. By the comparison of electrochemical oxidations in batch and flow we have found that continuous flow is able to outperform its batch counterpart, producing a good yield (71%) and a better enantiomeric excess (64%) than batch with a 98% conversion. We have, therefore, provided evidence that continuous flow chemistry has the potential to act as a new enabling technology to replace some aspects of conventional batch processes. </p>

Highly Stereoselective Aldol Reactions by Memory of Chirality: Synthesis of Quaternary β‐Hydroxy α‐Amino Acids

“…Because of their multiple interests, many ways to access quaternary α‐amino acids have been developed [6–10] . Among these, methods based on the principle of memory of chirality (MOC) [11–24] use as the only source of chirality the chirality of a natural α‐amino acid, the initial reactant, although it disappears transiently during the reaction. Our group has been interested in the development of asymmetric syntheses based on this principle for many years.…”