Aziridines and Azirines: Fused-ring Derivatives

Palladium-catalyzed allylic substitution between C-based nucleophiles and 6-azabicyclo[3.1.0]-hex-3-en-2-oxy derivatives: A new selectivity paradigm

“…Aziridines are the smallest members of the aza-heterocycle family [1,2]. Due to their considerable ring strain, these molecules show in general a high reactivity that makes them major intermediates for organic synthesis.…”

Synthesis of Structurally Diverse 3-, 4-, 5-, and 6-Membered Heterocycles from Diisopropyl Iminomalonates and SoftC-Nucleophiles

“…Diversely substituted aziridines are not only valuable synthetic intermediates but they also occur as substructures in natural products and druglike molecules. , Among these diverse families of aziridines, aziridine-2,2-diesters are special (i.e., donor–acceptor aziridines) as they serve as precursors of azomethine ylide intermediates that undergo a variety of cycloaddition reactions. , The synthesis of fully substituted aziridines remains a significant synthetic challenge . Since synthetic access to structurally diverse donor–acceptor aziridines is fairly limited, we saw an opportunity to access these valuable building blocks using an aza-Darzens reaction between haloester enolates and N -alkyl as well as N -aryl diisopropyl iminomalonates (Figure ).…”

“…The compound was purified by flash column chromatography (R f = 0.57 (20% EtOAc/ hexanes). 1 H NMR (600 MHz, CDCl 3 ): δ 7.89 (d,J = 7.4 Hz,2H),7.51 (t,J = 7.4 Hz,1H),7.40 (t,J = 7.8 Hz,2H),6.36 (s,1H),6.26 (s,2H),5.35 (s,1H), 5.13 (hept, J = 6.2 Hz, 2H), 4.13 (s, 2H), 2.18 (s, 6H), 1.22 (d,J = 6.3 Hz,6H),1.15 (d,J = 6.3 Hz,6H). 13 C{ 1 H} NMR (151 MHz,CDCl 3 ): δ 196.2,168.6,144.1,138.4,136.5,133.1,128.3,127.8,120.4,112.5,70.1,66.1,40.8,21.27,21.25,21 27c).…”

“…The compound was purified by flash column chromatography (R f = 0.49 (20% EtOAc/ hexanes). 1 H NMR (600 MHz, CDCl 3 ): δ 7.86 (d,J = 7.3 Hz,2H) 196.2, 168.7, 148.0, 140.8, 139.3, 136.4, 133.2, 128.4, 127.8, 108.1, 107.9, 100.5, 99.1, 70.2, 66.8, 40.7, 21.3, 21.2 27e). The general procedure was followed using acetophenone (0.58 mL, 4.9 mmol), KHMDS (1 M solution in THF) (5.32 mL, 5.3 mmol), and 3-trifluoromethylphenyl iminomalonate (1.1 g, 3.3 mmol) as starting materials to afford the ketone adduct as a white solid (0.82 g, 53%) (mp 132−134 °C).…”

“…The compound was purified by flash column chromatography (R f = 0.53 (20% EtOAc/hexanes). 1 H NMR (600 MHz, CDCl 3 ): δ 8.45 (d,J = 7.8 Hz,1H),7.91 (d,J = 8.2 Hz,1H),7.81 (d,J = 9.0 Hz,1H),7.68 (d,J = 7.1 Hz,1H),7.49 (p,J = 6.1,5.5 Hz,2H),7.38 (t,J = 7.7 Hz,1H),6.93 (d,J = 8.1 Hz,2H),6.61 (d,J = 8.4 Hz,2H),5.40 (s,1H), 5.18 (hept, J = 6.2 Hz, 2H), 4.21 (s, 2H), 2.20 (s, 3H), 1.28 (d,J = 6.3 Hz,6H), 1.19 (d,J = 6.3 Hz,6H). 13 C{ 1 H} NMR (151 MHz, CDCl 3 ): δ 200.…”