Reversible C=C Bond Activation by an Intramolecularly Coordinated Antimony(I) Compound

• Published in: Chemistry : a European journal Vol. 25; no. 56; pp. 12884 - 12888
• Main Authors: Kořenková, Monika, Hejda, Martin, Erben, Milan, Jirásko, Robert, Jambor, Roman, Růžička, Aleš, Rychagova, Elena, Ketkov, Sergey, Dostál, Libor
• Format: Journal Article
• Language: English
• Published: WEINHEIM Wiley 08.10.2019; Wiley Subscription Services, Inc
• Subjects: Activation; Antimony; Antimony compounds; Aromatic compounds; Benzene; C=C bond activation; chelates; Chemistry; Chemistry, Multidisciplinary; heterocycles; Physical Sciences; Pyrrolidine; Science & Technology; synthetic methods; antimony; BI; COMPLEXES; REACTIVITY; OXIDATIVE ADDITION; MAIN-GROUP ELEMENTS; SB; HYDROGEN; REDUCTION; heterocycles; STIBINIDENE; chelates; CHEMISTRY; C=C bond activation; synthetic methods
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201902968

The reaction of N,C,N‐chelated stibinidene ArSb (1) (Ar=C6H3‐2,6‐(CH=NtBu)2) with selected N‐alkyl/aryl‐maleimides RN(C(O)CH)2 (R=Me, tBu, Ph) gave the addition products with bridged bicyclic [2.2.1] structure containing an antimony atom at the bridgehead position, fused with a 6‐membered benzene and a 5‐membered N‐alkyl/aryl‐pyrrolidine ring. These compounds were completely characterized. More importantly, additional studies showed that these reactions are reversible in solution, thereby representing an unprecedented reversible activation of a C=C bond by an antimony(I) compound. Goes both ways: The first example of reversible activation of a C=C bond by a low‐valent antimony compound is presented. This process is ligand assisted, profiting from the non‐innocent behavior of the N,C,N‐pincer ligand and formally relies on a SbI−SbIII redox couple that functions under relatively mild reaction conditions.