Chiral 1,1′-binaphthylazepine derived amino alcohol catalyzed asymmetric Henry reaction

Diastereoselective and Highly Enantioselective Henry Reactions using C1‐Symmetrical Copper(II) Complexes

“…Enantioselective nitroaldol (Henry) reactions of CH 3 NO 2 and aromatic aldehydes have been intensively investigated using organocatalysis1 and metalorganic catalysts 2. However, there are only a few examples that demonstrate efficient reactions of aliphatic aldehydes3,4 and even less examples that use aliphatic aldehydes and prochiral nitroalkanes generating products with two chiral centres in high enantiomeric excess ( ee ) and high distereoisomeric ratio ( dr ) 2e,g,p–t…”

Synthesis and structures of copper complexes bearing unsymmetric derivatives of (R,R)‐1,2‐diaminocyclohexane: An efficient catalyst for asymmetric Henry reaction

“…The absolute configuration of the major product was assigned by comparison with the literature values …”

“…The crude products were purified by column chromatography (10% EtOAc/hexane) to give a colorless oil as ( S )‐1‐nitro‐4‐phenylbutan‐2‐ol . 1 H‐NMR (500 Hz, CDCl 3 ): δ 7.30 (5H, m, Ar‐ H ), 5.38 (1H, dd, ‐C H ), 4.51(1H, dd, C H 2 ), 4.41 (1H, dd, ‐C H 2 ), 2.89 (1H, br, s, ‐O H ).…”

“…The crude products were purified by column chromatography (10% EtOAc/hexane) to give a colorless oil as (S)-1nitro-4-phenylbutan-2-ol. [52,53] 1 H-NMR (500 Hz, CDCl 3 ): δ 7.30 (5H, m, Ar-H), 5.38 (1H, dd, -CH), 4.51(1H, dd, CH 2 ), 4.41 (1H, dd, -CH 2 ), 2.89 (1H, br, s, -OH). Enantiomeric excess (ee) was determined using HPLC on Chiral AD-H column (n-Hex:IPA = 90:10; flow rate = 1.0 ml/ min; λ = 254 nm); R enantiomer t R (minor) = 11 min, S enantiomer t R (major) = 17 min (Table 3).…”

“…This decrease in selectivity is attributed to the different configurations of stereogenic nitrogens present in the L 4 copper acetate The absolute configuration of the major product was assigned by comparison with the literature values. [52,60] e [L 1 Cu(OAc) 2 ] was used previously and presented here for comparison. [44] complex.…”