74498-78-5Relevant academic research and scientific papers
EFFET DE LA CONCENTRATION EN ACIDE FLUOROHYDRIQUE DANS LA PYRIDINE SUR LA STEREOSELECTIVITE DE LA FLUOROBROMATION DE CINNAMATES D'ETHYLE SUBSTITUTES.
Hamman, S.,Beguin, C. G.
, p. 515 - 524 (1983)
Bromofluorination of six substituted ethylcinnamates (e. g.YC6H4CX=CHCO2Et; Y = X = H, E and Z isomers; Y = mNO2, X = H; Y = pOCH3, X = H; and Y = H, X = Cl, E and Z isomers) with N-bromosuccinimide (NBS) in hydrogen fluoride-pyridine or hydrogen fluoride-tetrahydrofuran (several molar ratios), giving the Markovnikov-type regioselectivity has a stereoselectivity depending on several factors: the nature of the substituent (X or Y), the solvent (pyridine or THF) and mainly the hydrogen fluoride-solvent molar ratio.The variable importance of the complexation of the carbenium ion YC6H4C+XCHBrCO2Et as a complex between the olefin and NBS-hydrogen fluoride can give an interpretation of the influence of these factors on stereoselectivity.
