Addition Reactions of Nitroolefins

Modified cinchona alkaloids 18 and 19, derived from quinine and quinidine, respectively, were utilized by Deng and co-workers for the catalytic asymmetric Michael additions of malonates to nitroolefins [49]. These catalysts effectively promoted the conjugate additions of methylmalonate to a variety of aromatic (90-99% yield 96-98% ee), heteroaromatic (97-99% yield 96-98% ee) and aliphatic (71-86% yield 94% ee) -substituted nitroolefins (Table 6.7). As the two alkaloids 

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Seebach studied the conjugate addition reaction of nitroolefin 10 with butyllith-ium in the presence of the multidentate ligand 11 (accessible from tartaric acid), which yielded the adduct 12 in up to 58% ee (Scheme 4) [18]. 

Polysubstituted 3,4-dihydro-3-nitro-2ff-chromans are obtained from the enantioselective Michael—Michael cascade reaction of chalcone enolates and nitromethane catalyzed by bifunctional thiourea 19 (Scheme 31) (13JOC6488) and tandem Friedel—Crafts alkylation—Michael addition reaction of nitroolefin enoates and 1-methylindole promoted by Zn(OTf)2 (13S601).A squaramide-tertiary amine catalyst promotes the asymmetric sulfa-Michael—Michael cascade reaction of thiosalicylates with nitroalkene enoates which leads to polysubstituted chromans in high yields with excellent stereoselectivities (13OL1190). 

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