Dual nucleophilic phosphine photoredox catalysis is yet to be developed due to facile oxidation of the phosphine organocatalyst to the phosphoranyl radical cation. Herein, we report a reaction design that avoids this event and exploits traditional nucleophilic phosphine organocatalysis with photoredox catalysis to allow the Giese coupling with ynoates. The approach has good generality, while its mechanism is supported by cyclic voltametric, Stern-Volmer quenching, and interception studies.
View Article and Find Full Text PDFWe report a new visible-light-mediated carbonylative amidation of aryl, heteroaryl, and alkyl halides. A tandem catalytic cycle of [Ir(ppy) (dtb-bpy)] generates a potent iridium photoreductant through a second catalytic cycle in the presence of DIPEA, which productively engages aryl bromides, iodides, and even chlorides as well as primary, secondary, and tertiary alkyl iodides. The versatile in situ generated catalyst is compatible with aliphatic and aromatic amines, shows high functional-group tolerance, and enables the late-stage amidation of complex natural products.
View Article and Find Full Text PDFAn efficient nitro-Mannich type direct α-C(sp(3))-H functionalisation of N-aryl-1,2,3,4-tetrahydroisoquinolines catalysed by simple iron salts in combination with O2 as the terminal oxidant is described. The use of a Teflon AF-2400 membrane Tube-in-Tube reactor under continuous flow conditions allowed for considerable process intensification to be achieved relative to previous batch methods.
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