Kinetic effects in water and ethylene glycol. Application to high pressure organic synthesis
作者:Ge´rard Jenner、Ridha Ben Salem
DOI:10.1039/b000241k
日期:——
The kinetic effect of various Diels–Alder and Michael reactions is studied in water and ethylene glycol vs. organic solvents. The rate enhancement is considerable in water, much less in ethylene glycol. It is proposed that strong solvophobic interactions operate in water whereas the kinetic results in glycol are best explained by
hydrogen bonding and polarity effects. From a synthetic point of view, use of the properties of water (hydrophobic
interactions) or ethylene glycol (ionogenic medium) associated with the kinetic effect of high pressure may constitute an interesting multiactivation method to increase chemical reactivity. Examples of triactivation (high pressure catalytic Diels–Alder reactions in ethylene glycol) are given.
Effect of pressure on sterically hindered reactions with late transition states
作者:Badra Gacem、Gérard Jenner
DOI:10.1002/poc.718
日期:2004.3
The effect of high pressure is examined in two types of sterically congested reactions presenting late transitionstates: isopolar Diels–Alder cycloadditions of isoprene and quinones of various steric environment and conjugate additions of tert-butylamine and acrylic compounds. In the Diels–Alder cycloadditions, pressure has no enhanced kinetic sensitivity in sterically demanding reactions compared
Catalytic high pressure synthesis of hindered β-aminoesters
作者:Gérard Jenner
DOI:10.1016/0040-4039(94)02215-w
日期:1995.1
Hindered β-aminoesters are obtained in fair to high yields by the conjugate addition of amines to α,β-unsaturated esters, both substrates harbouring bulky groups, under highpressure in the presence of catalytic amounts of ytterbium triflate.