Metal free oxidation of vinamidine derivatives: a simple synthesis of α-keto-β-diimine ligands

Abstract

Oxidation of vinamidinium salts with meta-chloroperbenzoic acid not only provides access to new persistent 1,3-di(amino)oxyallyl radical cations, but also to α-keto-β-diimine ligands, for which no convenient synthesis was previously available.

16-Electron Half-Sandwich Rhodium(III), Iridium(III), and Ruthenium(II) Complexes as Lysosome-Targeted Anticancer Agents

“…This tedious process made it inconvenient to incorporate various substituents on the α-keto-β-diimine ligand. Recently, it was found that some α-keto-β-diimines could be prepared by a one-step reaction with m-CPBA as oxidant . Inspired by this work, m-CPBA was also employed to synthesize L1 – L3 (Scheme a).…”

Synthesis of new allylidene amino phenol-containing Schiff bases and metal complex formation using trimethinium salts

“…One of the useful attributes of many vinamidinium salts is their ease of preparation from substituted acetic acids under Vilsmeier-Haack conditions. [12][13][14][15][16][17][18][19][20][21][22][23] "In this study, our research group was able to prepare bsubstituted trimethinium salts with different R groups (including aryls and heteroaryls) from correspondingly substituted acetic acids, R-CH 2 CO 2 H, with good yields". 24,25 In continuation of this research on applications of trimethinium salts in organic synthesis (Scheme 1), [26][27][28][29][30][31] in this study, we report a new and highly efficient method for the synthesis of a novel class of allylidene amino phenol-containing Schiff bases from the reaction of trimethinium salts and diverse aminophenols in the presence of triethylamine, under catalyst-free conditions in EtOH at reux (Scheme 2).…”

“…One of the useful attributes of many vinamidinium salts is their ease of preparation from substituted acetic acids under Vilsmeier–Haack conditions. 12–23 “In this study, our research group was able to prepare β-substituted trimethinium salts with different R groups (including aryls and heteroaryls) from correspondingly substituted acetic acids, R–CH 2 CO 2 H, with good yields”. 24,25 …”

Air‐Stable Oxyallyl Patterns and a Switchable N‐Heterocyclic Carbene

“…They undergo thermal rearrangement through N!Oa ryl migration of substituents, [15,18] as well as one-electron oxidation at low potentials to yield highly air-persistent radical cations CC + . [15,19] However,t he half-life of even the most persistent stabilized oxyallyl C is less than one hour at room temperature. [19a, 20] Therefore,the design of isolable versions,not even to mention air stability,clearly requires significant additional steps.…”