Joshua P. Barham

1 Introduction Since the seminal modern reports of Yoon, Stephenson, and MacMillan in 2008/2009 [1-3], photoredox catalysis (PRC) has rapidly become one of the 21st century's most important new synthetic methods [4]. The central concept of PRC is simple: photoexcitation of a photocatalyst (PC, almost always closed-shell) into an excited state (*PC) grants it a higher energy electronic structure and hence notably enhanced redox power.

Abstract The introduction of diverse functionalities into omnipresent aliphatic C–H bonds is of notable value yet challenging in catalysis. While hydrogen atom transfer has emerged as a premier strategy, existing protocols frequently rely on O-centred radicals either generated from hazardous stoichiometric peroxides or within photocatalysts that are promiscuous in their excited state reactivity and non-conducive to structural tuning around the reactive centre.

1 Introduction Self-replication is considered a plausible process in the origins of life. The single-handedness of core biological compounds — such as sugars and amino acids — suggests that a mechanism might have existed to selectively amplify one enantiomer over the other.[1, 2] Self-replication or autocatalysis provides a convincing explanation for this phenomenon, as it enables small initial imbalances to be reinforced and amplified over time.