α,β-Unsaturated Carboxylic Acid Derivatives. VII. Reaction of Ethyl α,β-Unsaturated α-Cyanocarboxylates with Triethyl or Diethyl Phosphonate

DABCO-catalyzed regioselective cyclization reactions of β,γ-unsaturated α-ketophosphonates or β,γ-unsaturated α-ketoesters with allenic esters.

Highly efficient DABCO-catalyzed [4 + 2] cycloaddition of β,γ-unsaturated α-ketophosphonates or β,γ-unsaturated α-ketoesters with allenic esters gives the corresponding highly functionalized tetrahydropyran and dihydropyran derivatives in good to excellent yields and moderate to good regioselectivities under mild conditions.

Oxidative cleavage of unsaturated carboxylic acids (US)

Cp2TiCl2-catalyzed hydrocarboxylation of alkynes with CO2: formation of α,β-unsaturated carboxylic acids

a,b-Unsaturated carboxylic acids are important chemicals, and can be used as basic materials in the production of plastics, superabsorbent, polymers, and rubbers. Various synthetic methodologies for their synthesis have been developed, for example, oxidation of propene over heterogeneous catalysts at high temperature yielded the a,b-unsaturated carboxylic acids and hydrocarboxylation of alkynes...

Extended αβ associative memories

The αβ associative memories recently developed in Ref. 10 have proven to be powerful tools for memorizing and recalling patterns when they appear distorted by noise. However they are only useful in the binary case. In this paper we show that it is possible to extend these memories now to the gray-level case. To get the desired extension, we take the original operators α and β, foundation of the...

An organocatalytic asymmetric double Michael cascade reaction of unsaturated ketones and unsaturated pyrazolones: highly efficient synthesis of spiropyrazolone derivatives.

The first organocatalytic double Michael cascade reaction between unsaturated ketones and unsaturated pyrazolones has been developed which provides spiropyrazolone core structures containing two interval or three consecutive stereogenic centers with excellent diastereo- (>20:1) and enantioselectivities (up to 99% ee). Moreover, a pair of enantiomers and can be achieved via different catalysts.