2‐Benzamide Tellurenyl Iodides: Synthesis and Their Catalytic Role in CO₂ Mitigation

Abstract

Benzamide-derived organochalcogens (chalcogen = S, Se, and Te) have shown promising interest in biological and synthetic chemistry. Ebselen molecule derived from benzamide moiety is the most studied organoselenium. However, its heavier congener organotellurium is under-explored. Here, an efficient copper-catalyzed atom economical synthetic method has been developed to synthesize 2-phenyl-benzamide tellurenyl iodides by inserting a tellurium atom into carbon-iodine bond of 2iodobenzamides in one pot with 78-95 % yields. Further, the Lewis acidic nature of Te center and Lewis basic nature of nitrogen of the synthesized 2-Iodo-N-(quinolin-8-yl)benzamide tellurenyl iodides enabled them as pre-catalyst for the activation of epoxide with CO 2 at 1 atm for the preparation of cyclic carbonates with TOF and TON values of 1447 h À 1 and 4343, respectively, under solvent-free conditions. In addition, 2-iodo-N-(quinolin-8-yl)benzamide tellurenyl iodides have also been used as pre-catalyst for activating anilines and CO 2 to form a variety of 1,3-diaryl ureas up to 95 % yield. The mechanistic investigation for CO 2 mitigation is done by 125 Te NMR and HRMS studies. It seems that the reaction proceeds via formation of catalytically active TeÀ N heterocycle, an ebtellur intermediate which is isolated and structurally characterized.

Catalyst-free nucleophilic substitution of hydrogen in quinoline rings by acylethynylpyrroles: stereoselective synthesis of 2-(E-2-acylethenylpyrrolyl)quinolines

“…10 2-( N -Pyrrolyl)quinolines are ligands for platinum( ii ) emitters with tunable emission energies 11 and photoluminescent metal complexes for use in organic electroluminescent devices. 12 Recently, 13 8-aminoquinoline-tailored complexes with intramolecular selenium– or tellurium–nitrogen interactions were synthesized and found to be catalytically active in oxidation processes and CO 2 fixation. So, a novel straightforward route to this type of compound would represent a significant contribution to the chemistry of linked pyrrolylquinolines.…”

Direct Access to Thio- and Seleno-acetamides Bearing (Benzo)thiazoles by a Base-Promoted One-Pot Two-Step Three-Component Reaction of 2-Amino(benzo)thiazoles with Aryl Acetyl Chlorides and Dichalcogenides

“…The formation of carbon–chalcogen bonds has attracted considerable attention since the resulting products occur in various compounds of enormous practical importance, ranging from pharmaceuticals and agrochemicals to functional materials . The traditional Ullmann-type reaction, which has been well established in the past few decades, has provided successful synthetic protocols for organosulfur and organoselenium compounds through transition-metal catalyzed coupling reactions.…”

Directing Group Strategy for the Isolation of Organoselenium(VI) Benzoselenonates: Metal-Free Catalysts for Hydrogen Evolution Reaction

“…The synthesized hexavalent organoseleniums Se­(VI) are air-stable and could be stored without any noticeable reduction for a few months. The 8-aminoquinoline has been extensively used as a directing group for TM-catalyzed C–H bond functionalization, Recently, we have studied the role of quinoline ligand in the stabilization of synthetically difficult Te–N heterocycle and tetravalent spirotelluranes . Here, the quinoline ligand not only facilitated the installation of Se in the benzamide ring but also avoided the use of 1,10-phenanthroline ligand in catalysis as itself serves as a ligand and also helps in stabilizing high oxidation VI state of selenium.…”