A Striking Mode of Activation of Carbon Disulfide with a Cooperative Bis(silylene). Issue 2 (25th November 2021)

• Record Type: Journal Article
• Authors: Luecke, Marcel‐Philip; Giarrana, Luisa; Kostenko, Arseni; Gensch, Tobias; Yao, Shenglai; Driess, Matthias
• Is Part Of: Angewandte Chemie international edition. Volume 61:Issue 2(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-11-25
• Subjects: dearomatization -- silenes -- silicon -- small-molecule activation; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.202110398
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: The reactivity of the 1, 4‐substituted bis(silylenyl)terphenylene 1, 1, 4‐[ ortho ‐(LSi)C6 H4 ]2 C6 H4, (L=RC(NtBu)2, R=Ph, Mes) towards CS2 is reported. It results in a dearomatization of the phenylene ring, affording the 1, 3‐substituted cyclohexadiene derivative 2 . According to DFT calculations, a transient silene containing a Si=C bond capable of π(C=C) addition at the aromatic phenylene ring is a key intermediate. In contrast, addition of CS2 to the biphenyl‐substituted mono‐silylene ortho ‐(LSi)C6 H4 ‐C6 H5 3 leaves the aromatic π‐system intact and forms, in a [1+2] cycloaddition reaction, the corresponding thiasilirane 4 with a three‐membered SiSC ring. Further experimental studies led to the isolation of the novel mesoionic five‐membered Si2 S2 C heterocycle 6, which reacts with CS2 under C−C bond formation. All isolated new compounds were fully characterized and their molecular structures determined by single‐crystal X‐ray diffraction analyses. Abstract : An unexpected new type of cooperativity of the two silicon(II) atoms in a 1, 4‐terphenyl‐bridged bis(silylene) towards CS2 is reported and the results are compared with that of related mono‐silylenes. While a dearomatization occurs with the bis‐silylene, a novel mesoionic five‐membered Si2 S2 C heterocyclic compound, among other new products, results from stepwise degradation of CS2 with mono‐silylenes.