593-90-8Relevant articles and documents
Sabherwal,Burg
, p. 1001 (1970)
Love,P. et al.
, p. 2455 - 2462 (1968)
Rosenbaum,Symons
, p. 205,206 (1960)
Reaction of the Simmons-Smith reagent with trimethylamine-borane
Gragg,Ryschkewitsch
, p. 1988 - 1989 (1976)
-
Paterson,Onyszchuk
, p. 2324 (1961)
Indirect nuclear spin-spin coupling constants 1J( 17O,11B). First observation and calculation using density functional theory (DFT)
Wrackmeyer, Bernd,Tok, Oleg L.
, p. 949 - 955 (2006)
Coupling constants 1J(17O,11B) of borates, borane adducts and boranes with boron-oxygen bonds have been calculated on the basis of optimised molecular structures using the B3LYP/6-311+G(d,p) level of theory. This indicates that such coupling constants can be of either sign and that their magnitudes can be rather small. Since both 11B and 17O are quadrupole nuclei, it is therefore difficult to measure representative data. In the cases of trimethoxyborane and tetraethyldiboroxanes, it proved possible to obtain experimental data 1J( 17O,11B) (22 and 18 Hz) by measurement of 17O NMR spectra at high temperature (120 °C and 160 °C) respectively. The magnitude of these coupling constants is in reasonable agreement with calculated data. In the case of the diboroxane, this points towards a bond angle B-O-B more close to 180° than to 140°.
Holliday, A. K.,Thompson, N. R.
, (1960)
Bachmann et al.
, p. 261,262-263 (1975)
Nickel-Catalyzed CO2Rearrangement of Enol Metal Carbonates for the Efficient Synthesis of β-Ketocarboxylic Acids
Ninokata, Ryo,Yamahira, Tatsuya,Onodera, Gen,Kimura, Masanari
supporting information, p. 208 - 211 (2016/12/30)
4-Methylene-1,3-dioxolan-2-ones underwent oxidative addition of a Ni0catalyst in the presence of Me2Al(OMe), followed by a coupling reaction with alkynes, to form δ,?-unsaturated β-ketocarboxylic acids with high regio- and stereoselectivity. The reaction proceeds by [1,3] rearrangement of an enol metal carbonate intermediate and the formal reinsertion of CO2.
Nucleophilicity of Alkyl Zirconocene and Titanocene Precatalysts, and Kinetics of Activation by Carbenium Ions and by B(C6F5)3
Berionni, Guillaume,Kurouchi, Hiroaki,Eisenburger, Lucien,Mayr, Herbert
supporting information, p. 11196 - 11200 (2016/08/03)
Kinetics of activation of methyl and benzyl metallocene precatalysts by benzhydrylium ions, tritylium ions, and triarylborane B(C6F5)3were measured spectrophotometrically. The rate constants correlate linearly with the electrophilicity parameter E of the benzhydrylium and tritylium ions employed, allowing us to determine the σ-nucleophilicities of the metal–carbon bond of several zirconocenes and titanocenes. Bridging, substitution, metal, and ligand effects on the rates of metal–alkyl bond cleavage (M=Zr, Ti) were studied and structure–reactivity correlations were used to predict the kinetics of generation of metallocenium ions pairs, which are active catalysts in polymerization reactions and are highly electrophilic Lewis acids in frustrated Lewis pair catalysis.