The first "green" asymmetric organocatalytic reaction in a supercritical carbon dioxide medium was elaborated. Under the proposed conditions (100 bar, 35 °C), α-nitroalkenes enantioselectively accept diphenylphosphite in the presence of bifunctional organocatalysts bearing the tertiary amino group and the squaramide fragment to afford corresponding β-nitrophosphonates in high yields and with enantioselectivities of up to 94% ee. By varying the catalyst structure it is possible to synthesize both β-nitrophosphonate enantiomers under these conditions. A significant potential of the supercritical extraction for product isolation and catalyst recovery was demonstrated. † Electronic supplementary information (ESI) available. See

A very simple and highly efficient C2-symmetric tertiary amine-squaramide organocatalyst for asymmetric Michael reactions has been elaborated. In the presence of only 1 mol % of this catalyst, kojic acid derivatives and β-dicarbonyl compounds reacted with nitroolefins, affording the corresponding adducts in a nearly quantitative yield with an enantioselectivity up to 99% ee. The kojic acid-derived adducts could be efficiently produced under “green” conditions (in 96% EtOH or pure water). Moreover, due to the very low solubility in organic solvents, the developed nonsupported catalyst could be readily recovered and reused in catalytic reactions up to 7 times. Utmost availability (one-step synthesis without chromatographic purification), high level of stereoinduction, low efficient loading, and recyclability make it attractive for industrial application in the pharmaceutical industry.

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A green protocol for water-tolerant iminium-type asymmetric Michael reaction cooperatively catalyzed by 1,2-di(quinoline)ethane-1,2-diamine/mandelic acid was proposed.

Novel C-symmetric N,N'-bis-[(pyrrolidin-2-yl)methyl-squaramide] TFA salts bearing (R,R)- or (S,S)-1,2-di(pyridin-2-yl)ethane spacer groups were synthesized and applied, in combination with TEA, as efficient organocatalysts for asymmetric reactions between cyclohexanone derivatives and β-nitrostyrenes to afford the corresponding Michael adducts in high yields with good to excellent enantioselectivity. The catalytic procedure is readily scalable and recyclable over four times without a negative impact on the selectivity of the reaction. Some of the prepared compounds are valuable precursors to useful bioactive molecules.