The Knoevenagel condensation uses a catalytic base such as piperidine to convert an aldehyde or ketone and an activated methylene compound to a α,β-unsaturated dicarbonyl or related compound. The base deprotonates the methylene compound, creating a resonance stabilized enolate, which reacts with an iminium ion made from the carbonyl compound...

The Knorr pyrazole synthesis uses a catalytic acid to convert a hydrazine and 1,3-dicarbonyl compound to pyrazoles.  The dicarbonyl deprotonates the acid and is subsequently attacked by the hydrazine to produce an imine. The second nitrogen of the hydrazine then attacks the second carbonyl group to form a second imine....

The Kolbe-Schmitt reaction uses a base, carbon dioxide, and an acid work-up to convert a phenol to an ortho- or para- hydroxy benzoic acid. First the base deprotonates the phenol, forming phenoxide, which attacks carbon dioxide. Tautomerization and an acid work-up yields the final product. A large counterion such as...

The Fries rearrangement uses a Lewis or Brӧnsted acid to synthesize ortho- and/or para substituted phenolic ketones and aldehydes from phenolic esters. First an acylium cation is produced, which facilitates an electrophilic aromatic substitution to afford the ortho- and/or para-product. The ortho product is favored with high temperatures and no...

The Kumada cross-coupling reaction uses a palladium or nickel catalyst to couple an organohalide and a Grignard or organolithium reagent. The mechanism follows the expected oxidative addition-reductive elimination cycle. Reagents: Catalytic Palladium or Nickel Reactant: Organohalide, Organomagnesium or Organolithium Product: Coupled Product Type of Reaction: C-C Cross-Coupling Lab Tips Organolithium...

1.  Planning Experiments Avoid storing organolithium compounds, use them promptly after purchase. If storage is required, do so in an explosion-proof fridge that maintains a temperature of 10°C or lower. Become acquainted with your reagents before beginning to work with them; review SDS information for more information about storage, handling,...