pre-equilibrium in the formation of iminodiazonium (ID) ion and that the N2 liberation from the ID ion is rate-determining. Under high azide concentration conditions, where the effective reactant is the ID ion, the reaction gave a linear Hammett plot with a ρ value of −0.50. The observed substituent effects on the rate and the product selectivity imply that path bifurcation on the way from the rate-determining
[Reaction: see text] GaCl3 is found to be a superior catalyst for the skeletal rearrangement of alpha,alpha,alpha-trisubstituted aldehydes to ketones. The rearrangement can proceed smoothly in the presence of a catalytic amount of GaCl3, and even substrates having no heteroatoms alpha to the carbonyl group or without steric strains can be used. Double activation of a carbonyl group by two molecules
The present invention relates to processes for preparing certain 2-pyridones and 2-pyridinols, to novel compounds of these two types and to their use as biologically active compounds, in particular for controlling harmful microorganisms in crop protection, in the medicinal field and in the protection of materials.
excellent linear correlations with slopes of near unity. The results support the occurrence of path bifurcation after the rate-determining TS of the Beckmann rearrangement/fragmentation reaction, which has previously been proposed on the basis of molecular dynamics simulations. It was concluded that path-bifurcation phenomenon could be more common than thought and that a reactivity-selectivity argument based
Palladium-Catalyzed Mono-α-arylation of Carbonyl-Containing Compounds with Aryl Halides using DalPhos Ligands
作者:Sarah M. Crawford、Pamela G. Alsabeh、Mark Stradiotto
DOI:10.1002/ejoc.201200951
日期:2012.10
We report the extension and optimization of the [Pd(cinnamyl)Cl]2/DalPhos catalyst system, previously found effective for the mono-α-arylation of acetone, to the mono-α-arylation of a variety of carbonyl-containing compounds with aryl halides and heteroaryl halides. Aryl methyl ketones, heteroaryl methyl ketones, propiophenones, malonates, and methoxyacetone can be α-arylated under relatively mild