97-94-9Relevant articles and documents
ULTRASONIC IRRADIATION IN THE SYNTHESIS OF TRIETHYLBORANE FROM ETHYL BROMIDE VIA ETHYLALUMINIUM SESQUIBROMIDE
Liou, Kou-Fu,Yang, Paw-Hwa,Lin, Yih-Tsung
, p. 145 - 150 (1985)
Ethyl bromide and aluminum powder were irradiated with ultrasound to form ethylaluminum sesquibromide, which was then treated with triethyl borate to give triethylborane in satisfactory yield and purity.In comparison to other existing methods, ultrasonic irradiation seems to be a simple and effective process for the synthesis of organoboron compounds.
Synthesis and structural characterization of the first seven-vertex nido-carborane anion: nido-3,4-Et2C2B5H6-
Beck, Jeffrey S.,Quintana, William,Sneddon, Larry G.
, p. 1015 - 1016 (1988)
The reaction of closo-2,3-Et2C2B5H5 with Li-(BEt3)H in the presence of (CH3)4NCl has been found to result in the formation of the first seven-vertex nido-carborane anion nido-3,4-Et2C2B5H6-. A single-crystal X-ray study has demonstrated that the anion adopts an open-cage geometry based on a dodecahedron missing one five-connected vertex. Crystal data: space group P212121, Z = 4, a = 9.257 (1) ?, b = 9.359 (3) ?, c = 17.803 (2) ?. The structure was refined by full-matrix least squares to a final R of 0.055 and Rw of 0.064 for the 1128 unique reflections having Fo2 > 3σ(Fo2).
Bauer
, p. 5775,5777 (1956)
Lewis acid catalysis: Regioselective hydroboration of alkynes and alkenes promoted by scandium triflate
Mandal, Souvik,Verma, Piyush Kumar,Geetharani
supporting information, p. 13690 - 13693 (2019/01/03)
The first commercially available scandium-catalysed selective hydroboration of alkynes and alkenes with HBpin (pin = OC-Me2CMe2O) in the presence of a catalytic amount of NaHBEt3 has been developed. This protocol can be applicable to a wide range of substrates including aromatic, aliphatic with cyclic and acyclic side chains, and heteroaryl systems with broad functional-group compatibility. Mechanistic studies revealed that the reaction occurs in a syn fashion via the σ-bond metathesis between the alkenyl scandium species and HBpin.
Scope and post-transformations for the borane-isocyanide multicomponent reactions: Concise access to structurally diverse heterocyclic compounds
Kielland, Nicola,Vicente-Garcia, Esther,Reves, Marc,Isambert, Nicolas,Arevalo, Maria Jose,Lavilla, Rodolfo
, p. 3273 - 3284 (2013/12/04)
A recently described family of multicomponent reactions (MCRs) involving isocyanides, aldehydes, dipolarophiles and alkylboranes that yield highly substituted aziridines, oxazolidines and pyrrolidines has been studied in detail. In this work the scope of these processes is significantly increased by preparing the borane input through hydroboration of alkenes or organometallic processes, in tandem with the MCR. The aldehyde range is also expanded, and indole-3-carbaldehydes yield reactive imines and bis-indolyloxazolidines, depending on the electron density of the heterocycle. Finally, the obtained adducts constitute an ideal platform to generate structurally diverse compounds using simple post-condensation modifications. In this way, indole imines undergo stereoselective hydrocyanation and oxazolidines are reductively opened to give amino alcohols. Additionally, palladium-, ruthenium- and gold-catalyzed processes lead to a variety of complex heterocycles. The methodology is simple, efficient and highly divergent, leading to an array of interesting scaffolds for medicinal chemistry. Copyright
Electron-rich N-heterocyclic silylene (NHSi)-iron complexes: Synthesis, structures, and catalytic ability of an isolable hydridosilylene-iron complex
Blom, Burgert,Enthaler, Stephan,Inoue, Shigeyoshi,Irran, Elisabeth,Driess, Matthias
, p. 6703 - 6713 (2013/06/26)
The first electron-rich N-heterocyclic silylene (NHSi)-iron(0) complexes are reported. The synthesis of the starting complex is accomplished by reaction of the electron-rich Fe0 precursor [(dmpe)2Fe(PMe 3)] 1 (dmpe =1,2-bis(dimethylphosphino)ethane) with the N-heterocyclic chlorosilylene LSiCl (L = PhC(NtBu)2) 2 to give, via Me3P elimination, the corresponding iron complex [(dmpe)2Fe(←:Si(Cl)L)] 3. Reaction of in situ generated 3 with MeLi afforded [(dmpe)2Fe(←:Si(Me)L)] 4 under salt metathesis reaction, while its reaction with Li[BHEt3] yielded [(dmpe) 2Fe(←:Si(H)L)] 5, a rare example of an isolable SiII hydride complex and the first such example for iron. All complexes were fully characterized by spectroscopic means and by single-crystal X-ray diffraction analyses. DFT calculations further characterizing the bonding situation between the SiII and Fe0 centers were also carried out, whereby multiple bonding character is detected in all cases (Wiberg Bond Index >1). For the first time, the catalytic activity of a SiII hydride complex was investigated. Complex 5 was used as a precatalyst for the hydrosilylation of a variety of ketones in the presence of (EtO)3SiH as a hydridosilane source. In most cases excellent conversions to the corresponding alcohols were obtained after workup. The reaction pathway presumably involves a ketone-assisted 1,2-hydride transfer from the SiII to Fe0 center, as a key elementary step, resulting in a betaine-like silyliumylidene intermediate. The appearance of the latter intermediate is supported by DFT calculations, and a mechanistic proposal for the catalytic process is presented.
