Accessing aliphatic alcohols for metallaphotoredox catalyzed C(sp³)-arylation

Common cross-coupling reactions to obtain C(sp2)–C(sp3)-bonds are hampered by the abundance of nucleophilic and electrophilic functional groups. Recently in Nature, Dong and MacMillan developed a mild activation of a diverse range of alcohols with an N-heterocyclic carbene (NHC) salt and merged it with nickel photoredox dual catalytic arylation

Site‐Selective Electrochemical Oxidation of Carbohydrates

The site-selective transformation of unprotected sugars poses significant challenges to synthetic chemists but comes with a reward of step-economic and energy efficient protocols. By replacing stoichiometric oxidants with electricity, greener processes are anticipated. To date, mostly C3- and C6-selective transformations have been developed urging for further developments. Herein, we call for action to synthetic chemists to tackle the associated challenges of site-selective transformations of unprotected sugars toward challenging C2 and C4 regioisomers fueled by mild electroorganic transformations

Supramolecular Approaches for Taming the Chemo- and Regiochemistry of C60 Addition Reactions

The chemo- and regioselective functionalization of fullerenes is a long-standing problem of organic synthesis. Over the past five years, this fundamental challenge has gained technological relevance, because studies on single bis-adduct isomers in new-generation solar cells have demonstrated that the widespread use of isomer mixtures leads to suboptimal power conversion efficiencies. Herein, we review recent work on supramolecular approaches for achieving chemo- and regioselective syntheses of multiply functionalized derivatives of C60

Electrogenerated thianthrenium conjugate enables (Z)-selective allylic amination

Developing straightforward methodologies to access allylic amines is of contemporary importance in drug development and natural product synthesis. Recently, Wickens et al. developed an electrochemical approach with thianthrene adducts as reactive functional intermediates to transform terminal olefins and secondary amines into tertiary allylic amines in high yields and distinct Z-selectivity

Triplet Energy Transfer Mechanism in Copper Photocatalytic <i>N</i>‐ and <i>O</i>‐Methylation

Methylation reactions are chemically simple but challenging to perform under mild and non-toxic conditions. A photochemical energy transfer strategy was merged with copper catalysis to enable fast reaction times of minutes and broad applicability to N-heterocycles, (hetero−)aromatic carboxylic acids, and drug-like molecules in high yields and good functional group tolerance. Detailed mechanistic investigations, using kinetic analysis, aprotic MS, UV/Vis, and luminescence quenching experiments revealed a triplet-triplet energy transfer mechanism between hypervalent iodine(III) reagents and readily available photosensitizers

Incorporating sulfur into redox-active reagents and materials

Small sulfur-containing heterocycles, like thianthrenes and tetrathiafulvalenes, together with their larger π-extended counterparts, represent a long-known structural motif and offer reversible redox chemistry at low potentials. Recently these motifs gained an increasing interest in a variety of fields circulating organic chemistry ranging from molecular switches and redox reagents in synthesis to supramolecular aggregates. We anticipate fruitful developments from these versatile building blocks in modern technologies based on their reversible redox properties

Electrochemical Instability of Highly Fluorinated Tetraphenyl Borates and the Syntheses of their Respective Biphenyls

Highly fluorinated tetraphenyl borate anions are of importance as weakly coordinating anions in metalorganic reactions. However, at high positive potentials their electrochemical stability in organic solvents is not sufficient. This was investigated by a comprehensive cyclic voltammetry study and can be used synthetically to generate highly fluorinated biphenyls

Site-selective Electrochemical Oxidation of Glucosides

Quinuclidine-mediated electrochemical oxidation of glycopyranosides provides C3-ketosaccharides with excellent selectivity. The method is a versatile alternative to Pd-catalyzed oxidation, and to photochemical oxidation, and is complementary to the TEMPO-mediated C6-selective oxidation. Contrary to the electrochemical oxidation of methylene and methine groups, the reaction does not require oxygen