Asymmetric Michael Addition of Aromatic Ketones to Nitroolefins Catalyzed by Simple Chiral Bifunctional Primary Amine-Thioureas

Abstract

Simple chiral primary amine-thiourea catalysts derived from chiral 1,2-diphenylethylenediamine were found to catalyze direct Michael addition of aromatic ketones to nitroolefins with good enantioselectives (up to 86% ee) and excellent yields (up to 97%) for a broad range of substrates and successfully used in the preparation of (R)-Balcofen.

Organocatalysis for the Asymmetric Michael Addition of Cycloketones and α, β-Unsaturated Nitroalkenes

“…In a previous study [8,40], the optimized conditions for the stereoselective Michael addition reaction of acetophenone and nitrostyrene were investigated. Based on these conditions, various cycloketones, acetone and nitrostyrene derivatives were reacted in the presence of the catalyst, solvent, and a phenol group derivative (Table 1).…”

“…In this study, the asymmetric Michael reaction was applied to a cycloketone using (R, R)-1,2-diphenylethylenediamine (DPEN) as a catalyst. This reaction was also carried out in a previous study where the primary amine group of the DPEN-based catalyst was not N-monoalkylated [8,40]. The dehydration condensation reaction of the ketone and the diamine produces an enamine.…”

Organocatalysis for the Asymmetric Michael Addition of Cycloketones and α, β-Unsaturated Nitroalkenes

“…www.videleaf.com In this study, the asymmetric Michael reaction was applied to a cycloketone using (R, R)-1,2-diphenylethylenediamine (DPEN) as a catalyst. This reaction was also carried out in a previous study where the primary amine group of the DPENbased catalyst was not N-monoalkylated [8,40]. The dehydration condensation reaction of the ketone and the diamine produces an enamine.…”

Sequential Michael addition/retro-Claisen condensation of 1,3-diarylpropan-1,3-diones with nitrostyrenes: one-step synthesis of 4-nitro-1,3-diarylbutan-1-ones

“…As one of the main classes of ketone compounds, γnitro ketones are widely used as intermediates for the synthesis of various functionalized carbocycles. [3][4][5][6][7][8] The reported typical synthetically viable procedures for the construction of γ -nitro ketones include: i) the conjugate addition of nitromethane to chalcone; [9][10][11][12][13] ii) the detrifluoroacetylative Michael addition of 1-trifluoromethyl-1,3-diketones to conjugated nitroalkenes; 14 iii) the amine-catalyzed Michael addition of ketones to nitrostyrene; [15][16][17][18][19][20][21][22][23][24][25] iv) the nickel-catalyzed decarboxylative Michael addition of β-ketoacids to nitrostyrenes 26,27 (Scheme 1). However, some drawbacks, such as low yield, limited diversity and expensive substrates, still remains in the existing methods.…”