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The desymmetrization of N-(2-tert-butylphenyl)maleimides was realized by means of a Michael reaction of N-(tert-butoxycarbonyl)- 3-phenyloxindoles leading to the corresponding axially chiral succinimides in high yields. The use of a squaramide cinchonidine organocatalyst was fundamental to achieve the simultaneous remote control of the stereogenic axis and adjacent quaternary and tertiary stereocenters. [ABSTRACT FROM AUTHOR]

The first catalytic asymmetric Wittig reaction is presented. Hydrogen-bond donors catalyze the [2+2] cycloaddition reaction between stabilized phosphorus ylides and 4-substituted cyclohexanones, breaking their symmetry plane and furnishing axially chiral olefins with moderate stereoselectivities. [ABSTRACT FROM AUTHOR]

1,3-Dipolar cycloaddition of C-aryl- N-aryl- and C-carboxymethyl- N-aryl-nitrile imines with functionalized acetylenes have been studied. Regioisomeric mixtures have been obtained with the 5-substituted pyrazole as the major cycloadduct. Under scandium triflate catalysis a reversal in the regiochemistry was observed, especially in the case of C-carboxymethyl- N-aryl-nitrile imines. [ABSTRACT FROM AUTHOR]