Enantioselective Michael addition of anthrone to nitroalkenes catalyzed by bifunctional thiourea-tertiary amines

Enantioselective 1,6-Michael addition of anthrone to 3-methyl-4-nitro-5-alkenyl-isoxazoles catalyzed by bifunctional thiourea-tertiary amines

“…This highly enantioselective protocol gives a family of Michael adducts bearing an anthrone as well as a 3-methyl-4-nitro-isoxazole ring units in very high yields with good to high enantioselectivites, but a harsh temperature (À20 C) is needed. These studies carried out in this report further demonstrate that anthrone is a highly reactive carbon nucleophile 6,7 as well as 3-methyl-4-nitro-5-alkenyl-isoxazole is a kind of promising Michael acceptor in organic synthesis. 9 This methodology provides useful procedure for the synthesis of chiral anthrone derivatives.…”

“…In this area, as for the Michael donor, various carbon-centered nucleophiles including aldehydes and ketones, 2 malonate esters, 3 ketoesters, 4 and 1,3-diketones 5 have been extensively reported, by comparison, little progress has been made in the development of using anthrone as a nucleophile for the Michael addition reaction. 6,7 In parallel, as for the Michael acceptor, in contrast to often-used electrophiles, such as nitro olefins, a,b-unsaturated aldehydes, a,b-unsaturated ketones, and maleimides, 1,8 the number of methods that involved 3-methyl-4-nitro-5-alkenyl-isoxazoles as Michael acceptor is rather limited. 9 Therefore, it is easy to understand why there is no report about the Michael reaction of anthrone with 3-methyl-4-nitro-5-alkenyl-isoxazoles leading to chiral products bearing 3-methyl-4-nitro-isoxazole units so far.…”

Ar‐BINMOLs with Axial and sp3Central Chirality – Characterization, Chiroptical Properties, and Application in Asymmetric Catalysis

“…It has been reported that the Michael reaction of anthrone (6) with (E)-β-nitrostyrene (7) catalyzed by functional organocatalysts led to adducts with high enantiomeric excess through the hydrogen bonding activation of nitrostyrene. [19] Therefore, we initially chose the asymmetric Michael reaction of 6 with 7 as a model reaction to investigate the catalytic activity of 2. Initially, the screening commenced with different solvents in the presence of catalytic amount of 2a.…”

Substituent Effects on Regioselectivity of the Diels-Alder Reactions: Reactions of 10-Allyl-1,8-dichloroanthracene with 2-Chloroacrylonitrile, 1-Cyanovinyl Acetate and Phenyl Vinyl Sulfone

“…The importance of the Diels-Alder reaction arises from its reliability, versatility, and remarkable regio-stereoselectivity. Among all the dienes, anthracene derivatives have attracted considerable interest as one of the powerful dienes and their ability to react with various dienophiles through Diels-Alder reactions has been extensively investigated [2][3][4][5][6][7][8][9][10][11].…”

“…The investigation of the substituents effect on the Diels-Alder reaction of 10-allyl-1,8-dichloroanthracenes with dienophiles has not been reported yet. In this work, the regioselectivity of the Diels-Alder reaction of 10allyl-1,8-dichloroanthracenes (3) with 2-chloroacrylonitrile (4), 1-Cyanovinyl acetate (5), and Phenyl vinyl sulfone (10) has been studied. The structural elucidation of the cycloadducts has been made based on the NMR spectroscopic data.…”