A Diastereodivergent and Enantioselective Approach to syn- and anti-Diamines: Development of 2-Azatrienes for Cu-Catalyzed Reductive Couplings with Imines That Furnish Allylic Amines

Abstract

We introduce a new reagent class, 2-azatrienes, as a platform for catalytic enantioselective synthesis of allylic amines. Herein, we demonstrate their promise by a diastereodivergent synthesis of syn- and anti-1,2-diamines through their Cu–bis­(phosphine)-catalyzed reductive couplings with imines. With Ph-BPE as the supporting ligand, anti-diamines are obtained (up to 91% yield, >20:1 dr, and >99:1 er), and with the rarely utilized t-Bu-BDPP, syn-diamines are generated (up to 76% yield, 1:>20 dr, and 97:3 er).

Nickel-Catalyzed Intermolecular Reductive Coupling of Styrene and Its Derivatives with Imines Using Methanol as a Reductant

“…In 2008, they developed the first metal-catalyzed reductive coupling between vinyl pyridines and imines by using rhodium catalysis . Since then, many reductive couplings of imines with activated alkenes, such as vinyl aza-arenes, α,β-unsaturated esters, 1,3-dienes, allenes, tetrafluoroethylene, and enamines, have been reported. However, the intermolecular, reductive coupling of less active alkenes such as styrenes to common imines is rare (Figure a).…”

Assembly Studies of Two Planar Dy4 Single-Molecule Magnets

“…Field-dependent magnetizations (Figure c,d) were measured at 2, 3, and 5 K for 1 and 2 . They display similar behaviors of increasing quickly and slowly in the low- and high-field range, respectively, finally to 24.79 and 22.73 N μ B at 70 kOe at 2 K. It demonstrates possible low-lying energy states and/or anisotropy in the two Dy 4 compounds, which is further revealed by M versus HT –1 plots at various temperatures with non-superposition. − However, no significant magnetic hysteresis loops (Figure S13) could be observed at 2 K.…”

Development of regiodivergent asymmetric reductive coupling reactions of allenamides to access heteroatom-rich organic compounds

“…Besides the use of allenamides for the introduction of N-heteroatoms using reductive coupling, the Malcolmson group recently introduced the novel 2-azadiene 103,104 (80) and 2-azatriene 105 (84) reagents for the asymmetric synthesis of 1,2-aminoalcohols and 1,2-diamines by Cu-catalysed enantioselective reductive coupling (Scheme 14). While enantioselective coupling reactions with 2-azadienes (80) has been achieved with both ketone 103 and imine 104 electrophiles, saturated 1,2-aminoalcohols (83) or 1,2-diamines (82) are obtained.…”