Development of an anomalous heck reaction: Skeletal rearrangement of divinyl and enyne carbinols
(Chemical Equation Presented) A general set of conditions that achieves the union of aryl halides and divinyl or enyne carbinols to afford tri- or tetrasubstituted olefins in good yields (up to 83%) is described. The mechanism by which this proceeds is believed to involve the intermediacy of a cyclopropanol, followed by a novel skeletal reorganization. The ability to suppress β-hydride elimination of organopalladium intermediates appears to be critical to the success of these processes.
Ndungu, J. Maina,Larson, Kimberly K.,Sarpong, Richmond
p. 5845 - 5848
(2007/10/03)
One-Pot Synthesis of Homoallylic Ketones from the Addition of Vinyl Grignard Reagent to Carboxylic Esters
(Equation Presented) Fifteen homoallylic ketones have been synthesized in 26-77% yields on treatment of aromatic, aliphatic, and α-amino methyl carboxylates with excess vinylmagnesium bromide and catalytic amounts of a copper salt in THF. α-Amino homoallylic ketones derived from N-protected α-amino esters possessing aliphatic and alcohol side chains were synthesized in ≥98% enantiomeric purity.
Hansford, Karl A.,Dettwiler, James E.,Lubell, William D.
p. 4887 - 4890
(2007/10/03)
Reactions of Carbonyl Compounds with Grignard Reagents in the Presence of Cerium Chloride
The addition of Grignard reagents to ketones is significantly enhanced by cerium chloride with remarkable supression of side reactions, particularly enolization.Some esters, which are prone to side reactions, also react readily with Grignard reagents in the presence of cerium chloride to give normal reaction products in reasonable to high yields.