Stereospecific Alkene Aziridination Using a Bifunctional Amino-Reagent: An Aza-Prilezhaev Reaction

Abstract

In situ deprotection (TFA) of O-Ts activated N-Boc hydroxylamines triggers intramolecular aziridination of N-tethered alkenes to provide complex N-heterocyclic ring systems. Synthetic and computational studies corroborate a diastereospecific aza-Prilezhaev-type mechanism. The feasibility of related intermolecular alkene aziridinations is also demonstrated.

Synthesis of Fluorine‐Containing Molecular Entities Through Fluoride Ring Opening of Oxiranes and Aziridines

“…Bower and co‐workers successfully opened bicyclic aziridine 437 with phenylacetyl fluoride (Scheme ). The reagent activated the substrate as an N ‐acylaziridinium salt, which then underwent ring opening with the fluoride formed during the activation process …”

Catalytic Hydroetherification of Unactivated Alkenes Enabled by Proton‐Coupled Electron Transfer

“…Spectra are consistent with reported literature values. 19 1 H NMR (500 MHz, CDCl3, mixture of E/Z products) δ 7.29-7.22 (m, 0.1H), 7.13-7.05 (m, 0.9H), 7.03-6.97 (m, 0.2H), 6.93 (dd, J = 5.1, 3.6 Hz, 0.9H), 6.87 (d, J = 3.5 Hz, 0.9H), 6.61-6.49 (m, 1H), 6.07 (dt, J = 15.7, 7.0 Hz, 0.9H), 5.59 (dt, J = 11.4, 7.3 Hz, 0.1H), 3.70 (t, J = 6.5 Hz, 2H), 2.52 (qd, J = 7.…”

“…By adjusting the HAT co-catalyst loading to 30 mol%, tetrahydrofuran 2 was obtained in 85% yield, providing our optimal reaction conditions (entry 17). Control experiments run in the absence of light and photocatalyst furnished no product, and significantly reduced yields were observed in the absence of Brønsted base and HAT co-catalyst (entries [18][19][20][21]. For more easily oxidizable alkenes, such as trisubstituted and styrenyl olefins, diminished conversion to the desired ether products was observed, suggesting that an alternative but much less efficient alkene oxidation pathway could also be operative.…”

“…With respect to trisubstituted alkenes, anti-Markovnikov hydroetherification proceeded with primary, secondary, and tertiary alcohols (19)(20)(21)(22)(23)(24), providing ether products that are generally not accessible using traditional hydroalkoxylation strategies. Interestingly, products resulting from competing C-C β-scission were not observed during the formation of 23 and 24, enabling facile and efficient synthesis of spirocyclic scaffolds.…”

Catalytic Hydroetherification of Unactivated Alkenes Enabled by Proton-Coupled Electron Transfer

“…With respect to trisubstituted alkenes, anti-Markovnikov hydroetherification proceeded with primary, secondary, and tertiary alcohols (19)(20)(21)(22)(23)(24), providing ether products that are generally not accessible using traditional hydroalkoxylation strategies. Interestingly, products resulting from competing C-C β-scission were not observed during the formation of 23 and 24, enabling facile and efficient synthesis of spirocyclic scaffolds.…”