Direct Oxidative Carbon−Carbon Bond Formation Using the “Cation Pool” Method. 1. Generation of Iminium Cation Pools and Their Reaction with Carbon Nucleophiles

We have developed a method that involves the generation of a “cation pool” using low-temperature electrolysis, and then its reaction with nucleophiles under non-oxidative conditions. This one-pot method solves problems associated with conventional oxidative generation of cations and their in situ reaction with nucleophiles, and provides an efficient method for direct oxidative carbon−carbon bond formation. As an example of this method, generation of cation pools from carbamates by low-temperature electrolysis (−72 °C) and their reactions with carbon nucleophiles such as allylsilanes, enol silyl ethers, and enol acetates were examined and the desired products were obtained in good yields. Aromatic compounds and 1,3-dicarbonyl compounds can also be utilized as carbon nucleophiles. The present method was also applied to combinatorial parallel synthesis using a robotic synthesizer.