Asymmetric conjugate addition of nitroalkanes to enones with a chiral α-aminophosphonate catalyst

Primary Amino Acid Lithium Salt-Catalyzed Asymmetric Michael Addition of Carbon Nucleophiles to Enones

“…The enantioselectivity was determined by HPLC analysis (77% ee, Daicel CHIRALPAK AD-H, 5% isopropanol/hexane, 1.0 mL/min, 229 nm; t r (major enantiomer) = 18. Spectroscopic data of γ-nitroketones 4 are in agreement with published data [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32]. …”

“…As pioneering works in organocatalytic asymmetric Michael addition of carbon nucleophiles to α,β-unsaturated carbonyl compounds, Yamaguchi's group reported that Michael addition of malonates to enones could be catalyzed by a proline alkali metal salt [6][7][8][9][10][11][12]. They later succeeded in the asymmetric Michael addition of nitroalkanes to enones using a proline rubidium salt-catalyst [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32]. We recently reported that an O-silylated L-serine lithium salt was an effective catalyst for asymmetric Michael addition of malonates to enones to give various 1,5-ketoesters in good yields with high enantioselectivity [33].…”

Chemoselective Synthesis of α-Amino-α-cyanophosphonates by Reductive Gem-Cyanation–Phosphonylation of Secondary Amides

“…α-Aminophosphonic acids and their phosphonate esters as well as phosphono peptides exhibit diverse biological activities and have found wide applications in the areas of biological and medicinal chemistry as well as agriculture . They have also been used as important synthetic intermediates and organocatalysts in organic synthesis.…”

Enantioselective Synthesis of Quaternary α-Aminophosphonates via Conjugate Addition of α-Nitrophosphonates to Enones

“…Among the aminophosphonates, α-aminophosphonates received greater attention as compared to their β- and γ-analogs . Recently, α-aminophosphonates have been employed as organocatalysts in asymmetric aldol and Michael additions …”