This tutorial bridges an important knowledge gap by providing an easily accessible introduction that enables synthetic chemists to explore synthetic electrochemistry.

We have exploited a bis­(1,10-phenanthroline)­copper­(I) visible light photocatalyst (VLP), [Cu­(dap)2]+, to effect the direct α-C–H functionalization of amines. To our knowledge, this represents the first example of the oxidation of amines that are ultimately incorporated into synthetic targets by a copper­(I) VLP. We have utilized this approach to rapidly prepare unprecedented octahydroisoquinolino­[2,1-a]­pyrrolo­[3,4-c]­quinoline frameworks and exploited this process to synthesize a novel aglycone analogue of the natural product incargranine B. Most significantly, our studies suggest that the presence of trifluoroacetic acid (TFA) is crucial in mediating the aerobic oxidative quenching of a putative photoexcited copper­(I) species involved in the catalytic cycle.

Covering: 2008 to 2016The total synthesis of natural products and their derivatives continues to inspire organic chemists to identify and test new synthetic strategies and develop and explore novel methodology. In recent years, visible light photoredox catalysis has risen to prominence as a powerful technology that enables the selective formation of chemical bonds under mild reaction conditions. Herein we review applications of photoredox catalysis to the synthesis of natural products and related complex molecules, showcasing a range of powerful transformations that include: reductive couplings, photocycloadditions, intermolecular C-H functionalisation processes, fragmentations, and cyclisations.

It has been reported that pulsed irradiation can improve photosynthetic activity and phytochemical production in plants. Intrigued and inspired by these observations, we postulated that pulsed irradiation strategies may have broader implications in organic synthesis. We report here the results of a proof-of-concept study demonstrating that pulsed LED irradiation enhances the efficiency of a visible light-mediated photoredox-catalysed reaction. The design and construction of an inexpensive multiphase circuit (∼US$5) enabling power and pulse frequency modulation, which is connected to light-emitting diodes (LEDs), provides a source of pulsed visible light. This technology was then utilised to establish a novel copper-photocatalysed dual α-amino C-H/C-F functionalisation reaction. Pulsed blue LED irradiation was shown to be crucial for facilitating a much more efficient process and increasing the rate of product formation. Our results suggest that pulsed irradiation strategies have the potential to contribute to enhancing the synthetic utility and extending the scope of first row transition metal-based photoredox catalysts. We also anticipate that this approach will find wider applications in synthesis.