A Striking Mode of Activation of Carbon Disulfide with a Cooperative Bis(silylene)

Abstract

The reactivity of the 1,4-substituted bis(silylenyl)terphenylene 1,1 ,4-[ortho-(LSi)C 6 H 4 ] 2 C 6 H 4 ,( L = RC(NtBu) 2 , R = Ph, Mes) towards CS 2 is reported. It results in adearomatization of the phenylene ring, affording the 1,3-substituted cyclohexadiene derivative 2.A ccording to DFT calculations, at ransient silene containing aS i =Cb ond capable of p(C=C) addition at the aromatic phenylene ring is ak ey intermediate. In contrast, addition of CS 2 to the biphenyl-substituted monosilylene ortho-(LSi)C 6 H 4 -C 6 H 5 3 leaves the aromatic p-system intact and forms,i na[1+ +2] cycloaddition reaction, the corresponding thiasilirane 4 with athree-membered SiSC ring. Further experimental studies led to the isolation of the novel mesoionic five-membered Si 2 S 2 Ch eterocycle 6,w hich reacts with CS 2 under CÀCb ond formation. All isolated new compounds were fully characterized and their molecular structures determined by single-crystal X-rayd iffraction analyses.

Activation of CS2 with the 2H-Phosphindole Complex to Construct P,S-Polycycles

“…The P(1)–S(1) distance is 2.12 Å, whereas the P(2)–S(2) distance is 2.11 Å. Both C(21)–S(1) and C(21)–S(2) bond lengths are 1.87 Å, a value greater than the reference values (1.78–1.79 Å). , The C(17)–C(21)–S(1) and C(28)–C(21)–S(2) bond angles are 105.9° and 105.4°, respectively. These data suggest that the spiro-bicyclic ring and the spiro-carbon adopt a distorted tetrahedral geometry.…”

“…6 Driess et al reported a new cooperative activation of CS 2 by bridged bis(N-heterocyclic silylenes), resulting in the dearomatization of an intramolecular bridging benzene ring (Scheme 1a). 7 As depicted in Scheme 1b, the [3+2] cycloaddition reaction of disilenes with CS 2 generated Sheterocyclic carbenes. 8 N-Heterocyclic diazoolefins featuring a terminal N 2 group reacted readily with carbon disulfide to afford a [3+2] cycloaddition product in high yield (Scheme 1c).…”

“…Recently, important progress has also been made with the activation of CS 2 by low-coordinate main-group compounds . Driess et al reported a new cooperative activation of CS 2 by bridged bis­( N -heterocyclic silylenes), resulting in the dearomatization of an intramolecular bridging benzene ring (Scheme a) . As depicted in Scheme b, the [3+2] cycloaddition reaction of disilenes with CS 2 generated S-heterocyclic carbenes .…”

Synthetic, structural and reactivity studies of a boryl-ethynyl Silylene

“…9 Beyond these documented silylenes, the N-heterocyclic monochlorosilylene [LSi(:)Cl; L = PhC(N t Bu) 2 ] supported by an amidinato ligand was also applied to form covalent bonds with sp 2 - and sp 3 -hybridized carbon atoms. 10 In comparison with C sp 2 - and C sp 3 -ligands, C sp -ligands can not only act as relatively good σ-acceptors due to their high electronegativity, but also alternatively serve as π-donors through delocalized stabilization. However, to the best of our knowledge, there have been no reports to date on isolable silylenes bound to C sp -atoms at the Si( ii ) sites.…”

Microdroplet accelerated reaction for high-efficiency carbon disulfide conversion

“…2,3 The sulfur compounds, dithiocarbamates, xanthates, and thioureas synthesized using CS 2 can result in specific concentrations of CS 2 in the air. 4–8 These applications have led to widespread exposure to CS 2 and its adverse effects on human health. 9,10 Exposure to CS 2 has been associated with reduced sexual function, testicular atrophy, decreased sperm count, menstrual changes, abortion, premature birth, and an increased risk of malformation and congenital disabilities in offspring.…”