Inside Back Cover: Generation of Oxyphosphonium Ions by Photoredox/Cobaloxime Catalysis for Scalable Amide and Peptide Synthesis in Batch and Continuous‐Flow (Angew. Chem. Int. Ed. 5/2022)

Abstract

Amides are ubiquitous … …i nb iological and medicinal chemistry.I nt heir Research Article (e202112668), Jiannan Zhao and co-workers report an "oxidation-reduction condensation" reaction through the use of PPh 3 as an organic reductant. Synergistic cooperation between a Co(III) and an Ir(III) photoredox catalyst captures electrons from phosphorus and facilitates the formation of acyloxyphosphonium species,which enable direct amidation. Thes ynthetic utility of this photocatalytic method is highlighted by rapid gram-scale peptide synthesis and successful assembly of atetrapeptide through SPPS.

carba‐Nucleopeptides (cNPs): A Biopharmaceutical Modality Formed through Aqueous Rhodamine B Photoredox Catalysis

“…This is remarkable if you consider that our flow system has ≈4× less wattage (80 W for batch vs. 19.2 W for flow). While S−S, [47, 48] S−O, [49] S−C, [50, 51] and C−N [52] bond forming reactions have been achieved on peptides in flow by photoredox catalysis, our work represents the first example of C−C bond formation.…”

Electrochemical synthesis of oxazolesviaa phosphine-mediated deoxygenative [3 + 2] cycloaddition of carboxylic acids

“…When morpholine, a commonly used N -centered nucleophile, was added to the standard electrochemical conditions, the corresponding amide product h was obtained in 83% yield (Scheme 4c). 18 The above examples indicate that the key intermediates are not acyl radicals but more likely the cationic species. Furthermore, a “step-by-step” experiment demonstrated the anodic oxidation process via single electron transfer to generate the electrophilic intermediates and the following two-electron process with the nucleophilic site of isocyanides is simultaneous in this reaction system (Scheme 4d).…”

Progress of Catalytic Mitsunobu Reaction in the Two Decades

“…Furthermore, the Co(dmgH)(dmgH 2 )Cl 2 (dmgH = dime-thylglyoximate) could be compatible with the phosphine as reported recently. [101] On the other hand, the stoichiometric amount of reducing reagents, which are expensive and difficult to deal with, are required for the redox-driven system to recycle the phosphine oxide to the phosphine. In order to realize the catalytic cycle of organophosphorus in a greener and milder reaction condition, electroreduction might be the research direction since it substitutes chemical energy with electrical energy.…”