“…Also, given the harsh oxidative conditions of umpolung strategies, aldehydes are quite challenging substrates for C−H α-alkoxylation. 14 We were therefore pleased to see that Nalkoxypyridinium 8 reacted smoothly under our mild photoredox conditions to furnish α-alkoxylated aldehyde 9 in 52% yield (Scheme 3c). 15 As the formation of α-alkoxylated ketones 4 was inhibited in the presence of radical scavengers such as TEMPO ((2,2,6,6-tetramethylpiperidin-1-yl)oxyl) or in the absence of either photocatalyst or light (see Table 1), we presumed that a radical process was involved.…”