Discrete Complexes of 3d Metals with Monodentate Bulky Alkoxide Ligands and Their Reactivity in Bond Activation and Bond Formation Reactions

Synthesis of Chromium(II) Complexes with Chelating Bis(alkoxide) Ligand and Their Reactions with Organoazides and Diazoalkanes

“…C-C and C-H bond activation reactions featuring reactive chromium(IV)-imido were also reported [32]. As part of our ongoing investigation of nitrene-and carbene-transfer chemistry mediated by 3d metal complexes in bulky alkoxide ligand environments [33,34], we have reported the synthesis and reactions of chromium-imido complexes featuring two bulky monodentate alkoxides [OC t Bu 2 Ph] [31]. We have demonstrated that Cr IV (OC t Bu 2 Ph) 2 (NR') complexes, which were formed for bulky R' groups (R' = Mes, 2,6-Et 2 C 6 H 3 , 1-adamantyl), enabled catalytic transfer of the nitrene group [NR'] to isocyanides to form carbodiimides.…”

Catalytic synthesis of azoarenes via metal-mediated nitrene coupling

“…[38][39][40][41] In contrast, weak-field hard ligands (e.g., alkoxides, amides, and related ligands) are π-donors; their π-donation further competes with π-donation from the imido. 37,42 As a result, these ligands are likely to destabilize metal-nitrene functionality and yield less stable complexes but more reactive nitrene-transfer catalysts.…”

“…[56][57][58] Alkoxide ligands are good candidates to develop reactive and sustainable nitrene transfer catalysts incorporating middle and late transition metal centers. 37,42 Alkoxides are among the oldest and well-studied ligands in the arsenal of a synthetic chemist. [59][60][61][62][63][64] There are generally well-established efficient routes towards alkoxides.…”

“…[59][60][61][62][63][64] There are generally well-established efficient routes towards alkoxides. 42,[59][60][61] Alkoxides are generally considered σand π-donors. As a result, protio alkoxides are among the weakest-field ligands that nearly always lead to reactive high-spin complexes.…”

Synthesis and structure of a new bulky bis(alkoxide) ligand on a terphenyl platform

“…Bulky alkoxides are becoming increasingly used as ancillary ligands in group-transfer chemistry and catalysis (Brazeau & Doerrer, 2019;Chua & Duong, 2014;Hannigan et al, 2017;Jayasundara et al, 2018;Wannipurage et al, 2020). As a result of their stereoelectronic properties, profoundly weak-field bulky alkoxides enable formation of reactive low-coordinate high-spin middle and late transition-metal centers (Bellow et al, 2016b;Grass et al, 2019b). We have previously reported bulky monodentate alkoxides that led to reactive chromium and iron nitrene-transfer catalysts, (Bellow et al, 2015;Wannipurage et al, 2021;Yousif et al, 2015Yousif et al, , 2018 and a series of low-coordinate cobalt carbene complexes capable of carbene transfer to isocyanides (Bellow et al, 2016a;Grass et al, 2019aGrass et al, , 2020.…”