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

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 2‐iodobenzamides 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 CO2 at 1 atm for the preparation of cyclic carbonates with TOF and TON values of 1447 h−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 CO2 to form a variety of 1,3‐diaryl ureas up to 95 % yield. The mechanistic investigation for CO2 mitigation is done by 125Te NMR and HRMS studies. It seems that the reaction proceeds via formation of catalytically active Te−N heterocycle, an ebtellur intermediate which is isolated and structurally characterized. Insertion of tellurium into carbon‐iodine bond has been achieved for the first time by a base‐free copper‐catalyzed method for the construction of aryl 2‐benzamide tellurenyl iodides. Furthermore, synthesized tellurenyl iodides were explored for CO2 mitigation to synthesize cyclic carbonates and 1,3‐diaryl ureas, using epoxides and anilines, respectively. In addition, for the first time, the ebtellur intermediate is isolated and characterized by SC‐XRD.