N-Carbamate α-aminoalkyl-p-tolylsulfones—convenient substrates in the nitro-Mannich synthesis of secondary N-carbamate protected syn-2-amino-1-nitroalkanephosphonates

Fluorine-induced diastereodivergence discovered in an equally rare enantioselective syn-aza-Henry reaction

“…There is minimal literature related to the effect of uorine on the diastereo-and enantioselective addition of nitroalkanes bearing alternative activating groups. [31][32][33][34] To summarize, across Types I-IV, anti-diastereoselection is observed when using non-uorinated nitroalkanes. This is observed regardless of catalyst (1 or 2), reaffirming reports with PTC, 21 BAM, 35 and a wide range of other catalysts 4,36-38 with alkylsubstituted nitronates, and PTC [24][25][26] or BAM 14 catalysts applied to aryl-substituted nitronates.…”

Nitro-Mannich Reaction

“…In 2010, Gajda et al reported a racemic nitro-Mannich reaction of diethyl nitromethanephosphonate (173) (Scheme 108). 161 The authors demonstrated that tetrabutylammonium bromide (TBAB) was an effective PTC for reaction of diethyl nitromethanephosphonate (173) with N-carbamoyl imines formed in situ from α-amidosulfones. They used TBAB in combination with K 2 CO 3 for synthesis of a range of syn-α-nitroβ-aminophosphonates 174, which could be isolated in good yields (79−88%).…”

DFT-Based Stereochemical Rationales for the Bifunctional Brønsted Acid/Base-Catalyzed Diastereodivergent and Enantioselective aza-Henry Reactions of α-Nitro Esters

“…Most enantioselective aza-Henry reactions are anti -selective, with rare examples of syn -selective additions . Shibasaki has developed complementary anti - and syn -selective additions of nitroethane to N -Boc imines using Cu­(II)/Sm­(III)- and Yb­(III)-based catalysts, respectively, albeit with different ligand designs …”