At risk of showing my age, I recollect some 20-30 years’ ago now there was something of a proliferation of interest in organic electrochemistry, so a report by Huang et al caught my attention (Angew Chem, Int ed 2011, 50, 4, 924).  The authors describe the formation of a C-C bond through the reaction of allyl, benzyl and alkyl nucleophiles to imines.  The key is that the nucleophilic species are generated from the corresponding bromides by electrochemical reduction in aqueous ammonium bromide using zinc electrodes.  Therefore, viewing this chemistry from a ‘green’ perspective, one notes that they describe a reaction in an aqueous-THF medium generally in high yields from available starting materials at room temperature.  The reaction is outlined in the scheme below with allyl bromides.

 

Reading a later edition of the same journal I also noted a review by T Bach et al (Angew Chem, Int ed 2011, 50, 5, 1000) describing photochemical reactions in natural products synthesis.  I was reminded of some work I read last year by a group at Abbott (A Vasudevan et al, Tet Lett., 2010, 51, 4007) describing a flow system to conduct photolytic chemistry, which could surely render such chemistry scalable (possibly by scaling out rather than scaling up) and so bring this field of chemistry into focus for the practising PRD chemist.

These two papers together led me to the view that even if something has been explored in the past, there can be merit in re-visiting them and we should be mindful that a combination of established principles with later technologies can reap real dividends.