13737-09-2Relevant academic research and scientific papers
CO2 Conversion into Esters by Fluoride-Mediated Carboxylation of Organosilanes and Halide Derivatives
Frogneux, Xavier,Von Wolff, Niklas,Thuéry, Pierre,Lefèvre, Guillaume,Cantat, Thibault
supporting information, p. 2930 - 2934 (2016/03/25)
A one-step conversion of CO2 into heteroaromatic esters is presented under metal-free conditions. Using fluoride anions as promoters for the C-Si bond activation, pyridyl, furanyl, and thienyl organosilanes are successfully carboxylated with CO2 in the presence of an electrophile. The mechanism of this unprecedented reaction has been elucidated based on experimental and computational results, which show a unique catalytic influence of CO2 in the C-Si bond activation of pyridylsilanes. The methodology is applied to 18 different esters, and it has enabled the incorporation of CO2 into a polyester material for the first time. Metal free! A novel methodology is described to convert CO2 into heteroaromatic esters in the presence of organosilanes and organic halides using fluoride anions as promoters for the C-Si bond activation (see scheme). CO2 exhibits a unique catalytic influence in the C-Si bond cleavage of pyridylsilanes, serving as a traceless activator.
Unprecedented C-6 functionalisation of 3-picoline induced by a methyl to C-6 lithium shift
Mathieu, Julien,Gros, Philippe,Fort, Yves
, p. 951 - 952 (2007/10/03)
BuLi-Me2N(CH2)2OLi (BuLi-LiDMAE) promoted the clean C-6 functionalisation of 3-picoline via a methyl to C-6 lithium shift.
Synthesis and molecular structures of 2-trimethylsilyl-, 2-trimethylgermyl-, and 2-trimethylstannyl-pyridines
Riedmiller, Frank,Jockisch, Alexander,Schmidbaur, Hubert
, p. 13 - 17 (2007/10/03)
5-Methyl-2-trimethylsilyl-pyridine (1) has recently been prepared via the "in situ" Grignard reaction of 1-bromo-5-methyl-pyridine with magnesium and trimethylchlorosilane in refluxing tetrahydrofuran (thf) and structurally characterized. 2-Trimethylgermyl-(2) and 2-trimethylstannyl-pyridine (3) were now obtained from 2-bromo-pyridine through metallation (with n-BuLi) and treatment of the intermediates with Me3GeBr and Me3SnC1, respectively, in diethylether/ thf at -70°C. The crystal and molecular structure of compound 2 has been determined by low temperature (in situ) single crystal X-ray diffraction methods. There is a significant bending of the Me3Ge substituent towards the nitrogen heteroatom [Ge-C-N = 114.7(2)°]. This phenomenon is known from previous studies of the silicon analogue 1 to be not due to intramolecular (peripheral) Si/Ge←N coordination, but to be rather an intrinsic property of the heteroarene skeleton, as also confirmed by quantum-chemical calculations. Furthermore, there is no evidence for intermolecular coordination in the crystals. Such interactions could also be ruled out for the solution state of 2 and 3 through variable temperature multinuclear NMR investigations.
On the Mechanism of the Carbodesilylation of 4- or 5-Substituted 2-(Trimethylsilyl)pyridines
Effenberger, Franz,Krebs, Andreas,Willrett, Peter
, p. 1131 - 1140 (2007/10/02)
An "ylide mechanism" is proposed for the carbodesilylation of 2-(trimethylsilyl)pyridines with benzaldehyde.In contrast, 3- and 4-(trimethylsilyl)pyridines, react only in the presence of a base catalyst via pyridyl anions with electrophiles.The rates of the uncatalyzed carbodesilylation reactions of 4-substituted 2-(trimethylsilyl)pyridines 2 with benzaldehyde correlate very well with the resonance parameters of the substituents ?0R, whereas the rates of 5-substituted 2-(trimethylsilyl)pyridines 7 correlate with the inductive substituent parameters ?1 in the Taft equation.This is to our knowledge the first direct determination of the resonance parameters ?0R.Key Words: Pyridines, substituted 2-(trimethylsilyl)-, synthesis of, carbodesilylation of / Carbodesilylation / Rate constants
