32137-73-8Relevant articles and documents
Di(benzothiazol-2-yl)phosphanide as a janus-head ligand to caesium
Stey, Thomas,Pfeiffer, Matthias,Henn, Julian,Pandey, Sushil K.,Stalke, Dietmar
, p. 3636 - 3642 (2007)
Starting from tris(benzothiazol-2-yl)phosphane (1) an advanced Janus-head ligand, di(benzothiazol-2-yl)phosphane (2), was synthesised and structurally characterised. The heteroaryl substituents of this ligand provide both hard and soft donor sites. Surprisingly, the phosphorus atom in 2 is divalent and the hydrogen atom is directly bonded to one ring nitrogen atom and hydrogen bonded to the second. Compound 2 decomposes in any common solvent other than diethyl ether and a new preparation to improve the yields of 2 is presented. A coordination polymer, [{Cs(bth)2P}8] (3) (bth = benzothiazol-2-yl), was obtained when the sec-phosphane 2 was allowed to react with elemental caesium in a 1:1 ratio in diethyl ether at -78°C. In 3 each anion is coordinated to four caesium cations and vice versa. The central phosphorus atom is coordinated to two metal atoms above and below the mean plane of the anion in positions in which the two lone pairs of a four-electron donor are anticipated. Two additional cations μ-bridge both ring nitrogen atoms. Hence both faces of the Janus-head ligand are coordinated to the same number of metal cations but in a different way.
Nickel-Catalyzed C-H Silylation of Arenes with Vinylsilanes: Rapid and Reversible β-Si Elimination
Elsby, Matthew R.,Johnson, Samuel A.
supporting information, p. 9401 - 9407 (2017/07/22)
The reaction of C6F5H and H2C=CHSiMe3 with catalytic [iPr2Im]Ni(2-H2C=CHSiMe3)2 (1b) exclusively forms the C-H silylation product C6F5SiMe3 with ethylene as a byproduct ([iPr2Im] = 1,3-di(isopropyl)imidazole-2-ylidene). Catalytic C-H bond silylation is facile with partially fluorinated aromatic substrates containing two ortho fluorine substituents adjacent to the C-H bond and 1,2,3,4-tetrafluorobenzene. Less fluorinated substrates react slower. Under the same reaction conditions, catalytic [IPr]Ni(η2-H2C=CHSiMe3)2 (1a) ([IPr] = 1,3-bis[2,6-diisopropylphenyl]-1,3-dihydro-2H-imidazol-2-ylidene) provided only the alkene hydroarylation product C6F5CH2CH2SiMe3. Mechanistic studies reveal that the C-H activation and β-Si elimination steps are reversible under catalytic conditions with both catalysts 1a and 1b. With catalytic 1a, reversible ethylene loss after β-Si elimination was also observed despite its inability to catalyze C-H silylation; the reductive elimination step to form the silylation product is much slower than reductive elimination to form the alkene hydroarylation product. Reversible ethylene loss was not observed with 1b, which suggests that the rate-limiting step in the reaction is neither C-H activation nor β-Si elimination but either ethylene loss or reductive elimination of cis-disposed aryl and SiMe3 moieties.
General Reactivity of 2-Lithiobenzothiazole to Various Electrophiles and the Use as a Formyl Anion Equivalent in the Synthesis of α-Hydroxy Carbonyl Compounds
Chikashita, Hidenori,Ishibaba, Megumi,Ori, Keiji,Itoh, Kazuyoshi
, p. 3637 - 3648 (2007/10/02)
The reaction of 2-lithiobenzothiazole with a variety of electrophiles such as aldehydes, ketones, carboxylic esters, lactones, nitriles, and amides afforded the expected addition and substitution products.Trimethylsilyl chloride readily reacted with the b
