Selective Photooxidation of Sulfides Catalyzed by Bis‐cyclometalated Ir^III Photosensitizers Bearing 2,2′‐Dipyridylamine‐Based Ligands

Abstract

A new family of heteroleptic bis-cyclometalated Ir complexes with formula [Ir(CN^ ) (NN^ )]Cl (CN^ =2-phenylpyridinate and NN^ =2,2'-dipyridylamine or N-benzylated 2,2'-dipyridylamines, were synthesized, characterized, and successfully used as photosensitizers in the catalytic photooxidation of an array of dialkyl, dibenzyl, alkyl aryl, and diaryl sulfides, as well as sulfur-containing amino acids. Furthermore, the reactions proceeded with optimal chemoselectivity, and atom economy under mild conditions. Experimental observations support a dual mechanism in which singlet oxygen and superoxide are the actual oxidants.

Non-conventional synthesis and photophysical studies of platinum(ii) complexes with methylene bridged 2,2′-dipyridylamine derivatives

“…However, several side processes can diminish the reaction yield; for example, the reported yields of benzyldi(2pyridyl)amine vary from as high as 82% 28 to as low as 16%. 22 As we demonstrated in this work, the reaction becomes particularly problematic, when an electron withdrawing group is introduced in the phenyl ring (the same trend can also be found in another recent publication 29 ). In such case, the methylene group can be easier deprotonated by the base due to stabilization of the resulting anion, leading to undesired side reactions.…”

Dual Emissive Ir(III) Complexes for Photodynamic Therapy and Bioimaging

“…Simultaneously, a set of eight resonances (each integrating as 2H) is observed for the two orthometallated ligands, due to the C 2 symmetric nature of these complexes. Furthermore, another set of four resonances is observed for the two pyridyl rings present in the N^N ligands [ 30 ]. Similar shifts and 1 H NMR patterns were found for complexes 1 and 3 .…”

Non‐emissive RuII Polypyridyl Complexes as Efficient and Selective Photosensitizers for the Photooxidation of Benzylamines

“…Moreover, the two complexes with a nitro group in the sulfonamide ligand, [RuL4]Cl and [IrL4] , provided very low yields (entries 4 and 7 in Table ), thus suggesting that the presence of this functional group deactivates the excited state of the respective PC as previously reported . Further experiments were carried out for the active Ru II PC s decreasing the reaction time until 6 h to identify the most efficient PC and to establish possible structure–activity relationships (entries 10–13 in Table ).…”