Advances on asymmetric organocatalytic 1,4-conjugate addition reactions in aqueous and semi-aqueous media

Enabling protein-hosted organocatalytic transformations

“…In fact, taking into account the aqueous reaction medium, physiological pH (near 7.4) and temperature (near 37 C), 20 many of the reported organocatalysts do not function under biocompatible conditions. 8,10,17,[21][22][23][24][25][26][27][28][29][30][31] These boundaries vastly narrow the number of organocatalytic reactions applicable and, in response, efforts have been made to overcome limitations related to biocompatibility. 17,32,33 The use of proteins to host organocatalysts To enhance the biocompatibility of organocatalysis, biomolecules including DNA, RNA and proteins can be used to host the reactions.…”

“…16a) were prepared via either copper-catalysed azide-alkyne cycloaddition or amide bond coupling reactions. 39 These catalysts can be broadly segregated into three types: MacMillan-like imidazolidinones (16)(17)(18)(19), prolines (20,21) and pyrrolidines (22,23), and their ability to catalyse the Michael addition of nitromethane to aromatic a,b-unsaturated aldehydes was tested (Fig. 16b).…”

“…In fact, taking into account the aqueous reaction medium, physiological pH (near 7.4) and temperature (near 37 °C), 20 many of the reported organocatalysts do not function under biocompatible conditions. 8 , 10 , 17 , 21 – 31 These boundaries vastly narrow the number of organocatalytic reactions applicable and, in response, efforts have been made to overcome limitations related to biocompatibility. 17 , 32 , 33 …”

Stereoselective conjugate addition of ketones to alkylidene malonates using thiourea‐sulfonamide organocatalyst

“…Conjugate addition promoted by organocatalysts is an attractive synthetic methodology owing to their low toxicities and stabilities under air atmosphere. Asymmetric conjugate addition of carbon nucleophile to electron poor olefin using an organocatalyst is one of the most important reactions to form carboncarbon bonds in modern organic chemistry . Useful synthetic intermediates can be produced by selecting the combination of different Michael donors and acceptors.…”

“…Asymmetric conjugate addition of carbon nucleophile to electron poor olefin using an organocatalyst is one of the most important reactions to form carbon-carbon bonds in modern organic chemistry. [1][2][3][4] Useful synthetic intermediates can be produced by selecting the combination of different Michael donors and acceptors. The organocatalytic reactions of Michael donors such as aldehydes and ketones with electron deficient Michael acceptors such as α,β-unsaturated aldehydes, 5,6 ketones, 7-10 sulfones, 11,12 and nitrostylenes [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] are well investigated.…”