Scandium Phosphonioketene: Synthesis, Bonding and Reactivity. Issue 44 (9th July 2019)

• Record Type: Journal Article
• Authors: Mao, Weiqing; Wang, Yaya; Xiang, Li; Peng, Qian; Leng, Xuebing; Chen, Yaofeng
• Is Part Of: Chemistry. Volume 25:Issue 44(2019)
• Page Start: 10304
• Page End: 10308
• Publication Date: 2019-07-09
• Subjects: carbon monoxide -- density functional calculations -- insertion reaction -- ketenes -- scandium; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201902008
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: Reaction of a scandium phosphoniomethylidene with carbon monoxide provides the first scandium phosphonioketene (1 ). X‐ray diffraction analysis shows that the complex has a very short Sc−C bond (2.138(2) Å), and DFT calculations indicate that this unusual short bond length is due to the significant contribution of ionic coulomb interaction between carbon and scandium and the η 2 ‐O, C coordination fashion. Complex 1 is thermally stable, albeit shows high reactivity towards a series of unsaturated substrates, including carbon dioxide, ketone, imine, nitrile and isocyanide. In the reaction with tert ‐butyl isocyanide, not only an insertion of tert ‐butyl isocyanide into the Sc−C bond occur, but also a C−H activation on the phenyl ring. DFT calculations show that the reactivity of 1 operated by nucleophilic properties, and therefore the reaction mechanism favors the nucleophilic attack to isocyanide as a rate‐determining step, followed by the stepwise C−H activation through an interesting C−H deprotonation. Abstract : Sc‐intillating chemistry : The reaction of a scandium phosphoniomethylidene with carbon monoxide provides the first scandium phosphonioketene (1 ). Complex 1 shows high reactivity towards a series of unsaturated substrates, such as carbon dioxide as well as ketone, imine, nitrile and isocyanide, therefore showing an interesting coupling of CO with CO2 or an organic molecule. The bonding and reactivity of 1 were further highlighted by theoretical studies.