Stereoselective Synthesis Mediated by Light and Electricity

Stereoselective reactions are the core pillar of organic synthetic chemistry, especially regarding molecules of biological interest. Our research applied photochemistry and electrochemistry to synthesise chiral molecules as precursors for API. The photochemical approach was used in the [2+2] stereoselective cyclisation to afford a chiral cyclobutane derivative, an appealing scaffold with strategic importance as a building block due to its presence in various bioactive molecules. The strategy, inspired by the previous work of Reiser, makes use of the concept of chiral auxiliary to direct the synthesis in a stereoselective way, as shown in the following schema. The electrochemical approach focused on the stereoselective electrosynthesis of chiral diamine, particularly the piperazine ring, a well-known scaffold in many drugs. Piperazines are traditionally obtained by reacting an aldehyde with an amine in the presence of a transition metal in harsh conditions. Electrochemistry allowed us to replace redox reagents with "simple" electrons. Indeed, Okazaki of 1991, introduced a new synthetic approach for the synthesis of the piperazines ring. In addition, both syntheses were performed under continuous flow conditions with the aim of maximising productivity.