The quintessential theme of medicinal chemistry is probing structure activity relationships. While strategies such as de novo and diversity-oriented synthesis (DOS) are powerful tools to achieve this task, late-stage functionalization (LSF) is gaining traction over the past decade as it offers a quicker route to access libraries of complex bioactive molecules. Among the myriad of methods that could be applied for LSF reported thus far, C-H functionalization is undeniably an attractive and potent addition to a synthetic chemist's arsenal. This umbrella term has stretched in scope from traditional transition metal catalysis to organocatalytic, and photocatalytically-enabled transformations with recent examples applied to C-H functionalization of simple and complex amides through ionic or oxidative mechanisms. Trialkylamines and their proximal C-H positions are attractive loci for transformations especially as their privileged representation in their alkaloid family. The proclivity towards studying this class of compounds, however, is beyond their ubiquity; their relevance crosses the borders of natural sciences (Figure ). Moreover, rapid synthetic access to structurally-diverse trialkylamines is desired in pharmaceutical research as their minute structural variations carry substantial pharmacological effects, for instance, in the pharmacological activity of opiates. However, aside from the intrinsic basicity of amines, their C(sp )-H positions are relatively inert. Thus, access to derivatives are typically carried out via a stepwise fashion usually requiring initial demethylations of trialkylamine N-CH 3 groups to via free N-H for subsequent transformations. That is until the renaissance of single electron transfer (SET) redox methods, partly driven by photoredox catalysis, which revolutionized the practice of organic chemistry allowing direct C-C bond formations or nucleophilic additions to benzylic amines and a few examples on simple aliphatic amines. Still, reports on strategies for LSF of complex substrates -especially trialkylamines -are rather scarce. Direct transformation of a trialkylamine's N-CH 3 to an N-formyl group is another worthy endeavor as the structure of (and mechanisms to access) N-formyl groups is relevant to oxidative metabolite research, present in natural products, and could serve as a synthetic handle for further modifications including Barbier type amidation, C-C cross-coupling reaction, amino-carbonylation of alkenes or alkynes, and cross-coupling with phenols or amines affording carbamates or ureas . Classically, N-formyls are accessed from trialkylamines using toxic Ru(IV) or Os(IV) oxidants (Figure ) . Recently, Yamaguchi and co-workers circumvented this via an elegant Cu(II)/Cu(I) and Nitroxyl radical catalyst system. Song and co-workers reported a transition metal free deconstructive formylation reaction. The main drawbacks of such previous methods are i) the incompatibility of redox sensitive functionalities (commonly found on complex pharmaceuticals) hence limiting their application to relatively simple amines, ii) the expense of reagents (hindered nitroxyl radicals and excess difluorocarbene reagents) which are economically impractical for scale-up. These current challenges motivated us to develop a catalytic method that: i) utilizes the relatively mild conditions of visible light photocatalysis and abundant, benign reagents (O 2 ), ii) is applicable to complex pharmaceutically-relevant molecules as an LSF strategy, iii) is amenable to continuous flow processing in a scalable, safe process (Figure ).