Phosphine-mediated deoxygenative nucleophilic substitutions,s uch as the Mitsunobu reaction, are of great importance in organic synthesis.H owever,t he conventional protocols require stoichiometric oxidants to trigger the formation of the oxyphosphonium intermediates for the subsequent nucleophilic additions.Through dual catalysis of photoredox and cobaloxime,w er ealized ar adical strategy for the catalytic formation of acyloxyphosphonium ions that enables direct amidation. The deoxygenative protocol exhibits abroad scope and has been used in the late-stage amidation of drug molecules.I na ddition to batch reactions,acontinuous-flow reactor was developed, enabling rapid peptide synthesis on gram scale.T he successful assembly of at etrapeptide on the solid support further demonstrated the versatility of this photocatalytic system. Moreover,e xperimental and computational studies are consistent with the hypothesis of acyloxyphosphonium ions being formed as the key intermediates.Scheme 1. P-assisted deoxygenative substitutions.

The recent developments in asymmetric A3 (aldehyde–alkyne–amine) coupling has been summarized in this review. Several interesting modifications of the ligands enabled the highly enantioselective synthesis of chiral propargylamines, which are further used in the construction of nitrogen-containing chiral building blocks.

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.