Generation of carbon centered radicals from organic halides represents a powerful tool in modern organic chemistry, especially in the context of photoredox catalysis. However, activation of carbon–halogen bonds is usually promoted by toxic and hazardous tin reagents. Alternatively, α‐aminoalkyl radicals have emerged as a cheap and efficient halogen atom transfer (XAT) reagents, although the activation mechanism is still underexplored with respect to hydrogen atom transfer (HAT) chemistry. Herein, we report a computational systematic evaluation of four different α‐aminoalkyl radicals on the Halogen Atom Transfer (XAT) mechanism. We have evaluated up to 32 reactions, including two different types of substrates (Ph−X and Cy−X). This systematic study aims to provide a big picture on the key effects in this reactivity including the hybridization of carbon, the nature of the halogen, and the electronics/sterics of the α‐aminoalkyl radical.

The selective activation of a given C−H bond in complex molecules possessing bonds of similar polarity and strength remains one of the foremost challenges in hydrogen atom transfer (HAT) catalysis. Herein, we present the combination of photoredox and HAT catalysis with an oxophilic boron-based catalyst to achieve the chemoselective abstraction of α-hydroxy C−H bonds in β-amino alcohols. This enables us to access α-amino ketyl radicals, which are exploited for the direct synthesis of γ-oxo-δamino esters�a prominent scaffold in biologically active molecules.

The aza-Piancatelli reaction has been widely used to synthesize donor–acceptor Stenhouse adducts (DASAs), a new class of molecular photoswitches with unique properties. However, the substitution pattern of furan cores has been limited to position 3, as 3,4-disubstituted furans remain unreactive. Herein, we explore the aza-Piancatelli reaction mechanism using density functional theory (DFT) calculations to understand the influence of the different substituents on the reactivity. We found that all the reaction pathways are kinetically accessible, but the driving force of the reaction is lost in disubstituted furans due to the loss of conjugation in the DASA products. Finally, a simple model is proposed to guide the design of synthetic routes using this reaction.

The design of molecular solar fuels is challenging because of the long list of requirements these molecules have to fulfil: storage density, solar harvesting capacity, robustness, and heat release ability. All of these features cause a paradoxical design due to the conflicting effects found when trying to improve any of these properties. In this contribution, we will review different types of compounds previously suggested for this application. Each of them present several advantages and disadvantages, and the scientific community is still struggling to find the ideal candidate suitable for practical applications. The most promising results have been found using norbornadiene-based systems, although the use of other alternatives like azobenzene or dihydroazulene cannot be discarded. In this review, we primarily focus on highlighting the optical and photochemical aspects of these three families, discussing the recently proposed systems and recent advances in the field.

Photoredox catalysis has emerged as an alternative to classical cross-coupling reactions, promoting new reactivities. Recently, the use of widely abundant alcohols and aryl bromides as coupling reagents was demonstrated to promote efficient coupling through the Ir/Ni dual photoredox catalytic cycle. However, the mechanism underlying this transformation is still unexplored, and here we report a comprehensive computational study of the catalytic cycle. We have shown that nickel catalysts can promote this reactivity very efficiently through DFT calculations. Two different mechanistic scenarios were explored, suggesting that two catalytic cycles operate simultaneously depending on the concentration of the alkyl radical.