Organocatalyzed asymmetric Michael reaction of β-aryl-α-ketophosphonates and nitroalkenes

The first enantioselective Michael reaction of β-aryl-α-ketophosphonates and nitroalkenes has been realized by using a new bifunctional Takemoto-type thiourea catalyst. The primary Michael adducts obtained were converted in situ to the corresponding amides through the aminolysis. High yields, excellent diastereoselectivities (>95:5 dr), and good enantioselectivities (up to 81% ee) have been achieved for the corresponding α,β-disubstituted γ-nitroamides. This reaction again demonstrated that α-ketophosphonates are interesting pronucleophiles that can be used as amide surrogates in organocatalyzed reactions.